Config(3pm)

📦

version 5.42.3 · 10 versions

🎀 Config(3pm) 🎀

ok so first thing — the full header on this one is Config(3pm) Perl Programmers Reference Guide Config(3pm), and honestly the fact that they put the same name twice is giving "double-texting your bestie just to make sure she saw it." iconic behavior. anyway. let's get into it 💅

✨ NAME ✨

Config — access Perl configuration information

like, all of it. the whole lore. 🔥

✨ SYNOPSIS ✨

    use Config;
    if ($Config{usethreads}) {
        print "has thread support\n"
    }

    use Config qw(myconfig config_sh config_vars config_re);

    print myconfig();

    print config_sh();

    print config_re();

    config_vars(qw(osname archname));

✨ DESCRIPTION ✨

okay bestie so here's the tea 🫖 — the Config module is literally holding all the information that was available to the Configure program at the time Perl got built. and when she says all, she means it: over 900 values. no cap, over nine hundred.

Shell variables from the config.sh file (which is written by Configure) are stored in the read-only variable %Config, indexed by their names. so you just go $Config{whatever} and she hands it to you. 💖

Values that are stored in config.sh as 'undef' come back to you as undefined values. if you need to check whether a named variable even exists, use perl's exists function. (yes, the vibe check function. use it.)

for a description of the variables, please have a look at the Glossary file, as written in the Porting folder, or hit up this url:

https://github.com/Perl/perl5/blob/blead/Porting/Glossary

the functions, bestie 🦋

myconfig() — returns a textual summary of the major perl configuration values. see also "-V" in "Command Switches" in perlrun.
config_sh() — returns the entire perl configuration information in the form of the original config.sh shell variable assignment script. the whole thing. the full dump. 💀
config_re($regex) — like config_sh() but it returns, as a list, only the config entries whose names match the $regex. so it's the filter-influencer version of config_sh(). 🎀
config_vars(@names) — prints to STDOUT the values of the named configuration variables. each one gets printed on a separate line, in the form:

  name='value';

any names which are unknown get output as "name='UNKNOWN';". see also "-V:name" in "Command Switches" in perlrun. (shoutout to the UNKNOWN girlies, they're doing their best 🙈)

bincompat_options() — returns a list of C pre-processor options used when compiling this perl binary which affect its binary compatibility with extensions. bincompat_options() and non_bincompat_options() are shown together in the output of "perl -V" as Compile-time options.
non_bincompat_options() — returns a list of C pre-processor options used when compiling this perl binary which do not affect binary compatibility with extensions. the chill ones. 🧚
compile_date() — returns the compile date (as a string), equivalent to what's shown by "perl -V".
local_patches() — returns a list of the names of locally applied patches, equivalent to what's shown by "perl -V".
header_files() — returns a list of the header files that should be used as dependencies for XS code, for this version of Perl on this platform.

✨ EXAMPLE ✨

here's a more sophisticated example of using %Config, because we're not just doing $Config{osname} and calling it a day, we're doing character development ✨

    use Config;
    use strict;

    my %sig_num;
    my @sig_name;
    unless($Config{sig_name} && $Config{sig_num}) {
        die "No sigs?";
    } else {
        my @names = split ' ', $Config{sig_name};
        @sig_num{@names} = split ' ', $Config{sig_num};
        foreach (@names) {
            $sig_name[$sig_num{$_}] ||= $_;
        }
    }

    print "signal #17 = $sig_name[17]\n";
    if ($sig_num{ALRM}) {
        print "SIGALRM is $sig_num{ALRM}\n";
    }

⚠️ WARNING ⚠️

ok listen up, this part matters 👑

because this information is not stored within the perl executable itself, it's possible (but unlikely) that the information does not relate to the actual perl binary which is being used to access it. like, the receipts might be for a slightly different party. lowkey spooky but usually fine.

the Config module is installed into the architecture- and version-specific library directory ($Config{installarchlib}) and it checks the perl version number when loaded. so she does her own ID check at the door. 💅

the values stored in config.sh may be either single-quoted or double-quoted. double-quoted strings are handy for those cases where you need to include escape sequences in the strings. to avoid runtime variable interpolation, any "$" and "@" characters get replaced by "\$" and "\@", respectively. and this isn't foolproof, of course — so don't embed "\$" or "\@" in double-quoted strings unless you're willing to deal with the consequences. (the slashes will end up escaped and the "$" or "@" will trigger variable interpolation. messy. avoid. 🙈)

✨ GLOSSARY ✨

most "Config" variables are determined by the "Configure" script on platforms supported by it (which is most UNIX platforms). some platforms have custom-made "Config" variables, and may thus not have some of the variables described below, or may have extraneous variables specific to that particular port. see the port-specific documentation in such cases. (every port's got its own personality, we respect it.)

🌸 P 🌸

PERL_API_REVISION — from patchlevel.h:

this number describes the earliest compatible "PERL_REVISION" of Perl ("compatibility" here being defined as sufficient binary/"API" compatibility to run "XS" code built with the older version). normally this does not change across maintenance releases. please read the comment in patchlevel.h. 📖

PERL_API_SUBVERSION — from patchlevel.h:

this number describes the earliest compatible "PERL_SUBVERSION" of Perl ("compatibility" here being defined as sufficient binary/"API" compatibility to run "XS" code built with the older version). normally this does not change across maintenance releases. please read the comment in patchlevel.h.

PERL_API_VERSION — from patchlevel.h:

this number describes the earliest compatible "PERL_VERSION" of Perl ("compatibility" here being defined as sufficient binary/"API" compatibility to run "XS" code built with the older version). normally this does not change across maintenance releases. please read the comment in patchlevel.h.

PERL_CONFIG_SH — from Oldsyms.U:

this is set to "true" in config.sh so that a shell script sourcing config.sh can tell if it has been sourced already. (she's checking if you already texted her. it's called boundaries. 🫶)

PERL_PATCHLEVEL — from Oldsyms.U:

this symbol reflects the patchlevel, if available. will usually come from the .patch file, which is available when the perl source tree was fetched with rsync.

PERL_REVISION — from Oldsyms.U:

in a Perl version number such as 5.6.2, this is the 5. this value is manually set in patchlevel.h. ✨

PERL_SUBVERSION — from Oldsyms.U:

in a Perl version number such as 5.6.2, this is the 2. values greater than 50 represent potentially unstable development subversions. this value is manually set in patchlevel.h. (so if your subversion is being extra, that's why 💀)

PERL_VERSION — from Oldsyms.U:

in a Perl version number such as 5.6.2, this is the 6. this value is manually set in patchlevel.h.

🌈 _ 🌈

_a — from Unix.U:

this variable defines the extension used for ordinary library files. for unix, it is .a. the . is included. other possible values include .lib.

_exe — from Unix.U:

this variable defines the extension used for executable files. "DJGPP", Cygwin and OS/2 use .exe. Stratus "VOS" uses .pm. on operating systems which do not require a specific extension for executable files, this variable is empty. (empty is a valid vibe. 💅)

_o — from Unix.U:

this variable defines the extension used for object files. for unix, it is .o. the . is included. other possible values include .obj.

🦋 a 🦋

afs — from afs.U:

this variable is set to "true" if "AFS" (Andrew File System) is used on the system, "false" otherwise. it is possible to override this with a hint value or command line option, but you'd better know what you are doing. 👀

afsroot — from afs.U:

this variable is by default set to /afs. in the unlikely case this is not the correct root, it is possible to override this with a hint value or command line option. this will be used in subsequent tests for AFSness in the configure and test process. (AFSness. that's a real word in here. we love her. 🍓)

alignbytes — from alignbytes.U:

this variable holds the number of bytes required to align a double—or a long double when applicable. usual values are 2, 4 and 8. the default is 8, for safety. 🛟

aphostname — from d_gethname.U:

this variable contains the command which can be used to compute the host name. the command is fully qualified by its absolute path, to make it safe when used by a process with super-user privileges. 🔒

api_revision — from patchlevel.U:

the three variables, api_revision, api_version, and api_subversion, specify the version of the oldest perl binary compatible with the present perl. in a full version string such as 5.6.1, api_revision is the 5. prior to 5.5.640, the format was a floating point number, like 5.00563.

perl.c:incpush() and lib/lib.pm will automatically search in $sitelib/.. for older directories back to the limit specified by these api_ variables. this is only useful if you have a perl library directory tree structured like the default one. see "INSTALL" for how this works. the versioned site_perl directory was introduced in 5.005, so that is the lowest possible value. the version list appropriate for the current system is determined in inc_version_list.U.

"XXX" To do: since compatibility can depend on compile time options (such as bincompat, longlong, etc.) it should (perhaps) be set by Configure, but currently it isn't. currently, we read a hard-wired value from patchlevel.h. perhaps what we ought to do is take the hard-wired value from patchlevel.h but then modify it if the current Configure options warrant. patchlevel.h then would use an #ifdef guard. (the classic "we should really fix this" note. deeply relatable. 😭)

api_subversion — from patchlevel.U:

api_version — from patchlevel.U:

the three variables, api_revision, api_version, and api_subversion, specify the version of the oldest perl binary compatible with the present perl. in a full version string such as 5.6.1, api_version is the 6. see api_revision for full details. as a special case, 5.5.0 is rendered in the old-style as 5.005. (in the 5.005_0x maintenance series, this was the only versioned directory in $sitelib.) 🎀

api_versionstring — from patchlevel.U:

this variable combines api_revision, api_version, and api_subversion in a format such as 5.6.1 (or 5_6_1) suitable for use as a directory name. this is filesystem dependent. ✨

ar — from Loc.U:

and then the page just... stops right there, mid-sentence, no description. cliffhanger. the rest of ar is coming in the next part, bestie, don't come for me 💀

…and to wrap this entry up: this variable is used internally by Configure to figure out the full pathname (if there's one) of the ar program. After Configure runs, the value gets reset to a plain "ar" and is, respectfully, not useful anymore.
archlib — From archlib.U: This one holds the name of the directory where the user wants the architecture-dependent public library files for $package to live. Usually it's a local dir like /usr/local/lib. Programs using this variable have to be ready to deal with filename expansion, no cap. 🗂️
archlibexp — From archlib.U: Literally the same as archlib, except it's filename-expanded at configuration time so it's convenient to use. Same vibe, pre-glow-up. ✨
archname — From archname.U: A short name that characterizes the current architecture. It's used mainly to construct the default archlib. It's giving "name tag at the function". 🏷️
archname64 — From use64bits.U: This variable is used for the 64-bitness part of $archname. That's it, that's the whole job. 🧮
archobjs — From Unix.U: Defines any additional objects that must be linked in with the program on this architecture. On unix it's usually empty. Typically used to include emulations of unix calls or other facilities — for perl on OS/2, for example, this would include os2/os2.obj. 🧩
asctime_r_proto — From d_asctime_r.U: This one encodes the prototype of asctime_r. It's zero if d_asctime_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_asctime_r is defined. Binary icon 💅
awk — From Loc.U: Used internally by Configure to determine the full pathname (if any) of the awk program. After Configure runs, the value is reset to a plain "awk" and is not useful. You see the pattern by now, bestie.

b 🎀

baserev — From baserev.U: The base revision level of this package, straight from the .package file. Receipts! 🧾
bash — From Loc.U: This variable is defined but not used by Configure. The value is the empty string and is not useful. She exists and she does nothing and honestly? Same. 💀
bin — From bin.U: Holds the name of the directory where the user wants the publicly executable images for the package in question to go. Most often a local directory like /usr/local/bin. Programs using this variable must be prepared to deal with ~name substitution. 🛠️
bin_ELF — From dlsrc.U: Saves the result from configure if generated binaries are in "ELF" format. Only set to defined when the test has actually been performed and the result was positive. No vibes-based guessing here. 🔍
binexp — From bin.U: Same as the bin variable but filename-expanded at configuration time, for use in your makefiles. 🍓
bison — From Loc.U: Used internally by Configure to determine the full pathname (if any) of the bison program. After Configure runs, the value is reset to a plain "bison" and is not useful. (iykyk by now)
byacc — From Loc.U: Used internally by Configure to determine the full pathname (if any) of the byacc program. After Configure runs, the value is reset to a plain "byacc" and is not useful. Yep, another one. 🎀
byteorder — From byteorder.U: Holds the byte order in a UV. In the following, larger digits indicate more significance. The variable byteorder is either 4321 on a big-endian machine, or 1234 on a little-endian, or 87654321 on a Cray … or 3412 with weird order ! Cray said "I'm different" and honestly iconic of her. 🌀

c 🦋

c — From n.U: Contains the \c string if that is what causes the echo command to suppress newline. Otherwise it is null. Correct usage is $echo $n "prompt for a question: $c". Not me being a whole variable with a one-letter name 😭
castflags — From d_castneg.U: Contains a flag that precise difficulties the compiler has casting odd floating values to unsigned long: 0 = ok, 1 = couldn't cast < 0, 2 = couldn't cast >= 0x80000000, 4 = couldn't cast in argument expression list. Main character bitmask energy. 🌈
cat — From Loc.U: Used internally by Configure to determine the full pathname (if any) of the cat program. After Configure runs, the value is reset to a plain "cat" and is not useful. 🐈
cc — From cc.U: Holds the name of a command to execute a C compiler which can resolve multiple global references that happen to have the same name. Usual values are "cc" and "gcc". Fervent "ANSI" compilers may be called "c89". "AIX" has xlc. Respect the classics. 💜
cccdlflags — From dlsrc.U: Contains any special flags that might need to be passed with "cc -c" to compile modules to be used to create a shared library that will be used for dynamic loading. For hpux, this should be +z. It's up to the makefile to use it. 🧚
ccdlflags — From dlsrc.U: Contains any special flags that might need to be passed to cc to link with a shared library for dynamic loading. It's up to the makefile to use it. For sunos 4.1, it should be empty. Empty is a valid look, bestie. ✨
ccflags — From ccflags.U: Contains any additional C compiler flags desired by the user. It's up to the Makefile to use this. 👑
ccflags_uselargefiles — From uselfs.U: Contains the compiler flags needed by large file builds and added to ccflags by hints files. Big file energy only. 📦
ccname — From Checkcc.U: This can set either by hints files or by Configure. If using gcc, this is gcc, and if not, usually equal to cc, unimpressive, no? Some platforms, however, make good use of this by storing the flavor of the C compiler being used here. For example, if using the Sun WorkShop suite, ccname will be "workshop". Glow-up arc fr fr. 🌟
ccsymbols — From Cppsym.U: Contains the symbols defined by the C compiler alone. The symbols defined by cpp or by cc when it calls cpp are not in this list, see cppsymbols and cppccsymbols. The list is a space-separated list of symbol=value tokens. 🔖
ccversion — From Checkcc.U: This can set either by hints files or by Configure. If using a (non-gcc) vendor cc, this variable may contain a version for the compiler. 🏷️
cf_by — From cf_who.U: Login name of the person who ran the Configure script and answered the questions. This is used to tag both config.sh and config_h.SH. Shoutout to whoever answered all that. 🫶
cf_email — From cf_email.U: Electronic mail address of the person who ran Configure. This can be used by units that require the user's e-mail, like MailList.U. 💌
cf_time — From cf_who.U: Holds the output of the date command when the configuration file was produced. This is used to tag both config.sh and config_h.SH. Timestamped for the gods. ⏰
charbits — From charsize.U: Contains the value of the CHARBITS symbol, which indicates to the C program how many bits there are in a character. 🧮
charsize — From charsize.U: Contains the value of the CHARSIZE symbol, which indicates to the C program how many bytes there are in a character. Yes, bits and bytes are different variables, keep up bestie. 💅
chgrp — From Loc.U: This variable is defined but not used by Configure. The value is the empty string and is not useful. 🙈
chmod — From Loc.U: Used internally by Configure to determine the full pathname (if any) of the chmod program. After Configure runs, the value is reset to a plain "chmod" and is not useful. 🔐
chown — From Loc.U: This variable is defined but not used by Configure. The value is the empty string and is not useful. 🫥
clocktype — From d_times.U: Holds the type returned by times(). It can be long, or clock_t on "BSD" sites (in which case <sys/types.h> should be included). Include the header or perish. 📟
comm — From Loc.U: Used internally by Configure to determine the full pathname (if any) of the comm program. After Configure runs, the value is reset to a plain "comm" and is not useful. (Not the comm you're thinking of, different girl.) 🎀
compiler_warning — From compiler_warning.U: Holds the command to check if the file specified as a parameter contains a compiler warning. Snitching on your compiler, but make it a variable. 🚨
compress — From Loc.U: This variable is defined but not used by Configure. The value is the empty string and is not useful. 📭
config_arg0 — From Options.U: Contains the string used to invoke the Configure command, as reported by the shell in the $0 variable. 💫
config_argc — From Options.U: Contains the number of command-line arguments passed to Configure, as reported by the shell in the $# variable. The individual arguments are stored as variables config_arg1, config_arg2, etc. 🔢
config_args — From Options.U: Contains a single string giving the command-line arguments passed to Configure. Spaces within arguments, quotes, and escaped characters are not correctly preserved. To reconstruct the command line, you must assemble the individual command line pieces, given in config_arg[0-9]*. They said "lossy" and meant it 😭
contains — From contains.U: Holds the command to do a grep with a proper return status. On most sane systems it is simply "grep". On insane systems it is a grep followed by a cat followed by a test. This variable is primarily for the use of other Configure units. Insane systems stay catching strays 💀
cp — From Loc.U: Used internally by Configure to determine the full pathname (if any) of the cp program. After Configure runs, the value is reset to a plain "cp" and is not useful. 🗂️
cpio — From Loc.U: This variable is defined but not used by Configure. The value is the empty string and is not useful. 🫧
cpp — From Loc.U: Used internally by Configure to determine the full pathname (if any) of the cpp program. After Configure runs, the value is reset to a plain "cpp" and is not useful. Note: cpp ≠ cppflags, do not confuse the girls. 💅
cpp_stuff — From cpp_stuff.U: Contains an identification of the concatenation mechanism used by the C preprocessor. Mysterious but make it iconic. 🧵
cppccsymbols — From Cppsym.U: Contains the symbols defined by the C compiler when it calls cpp. The symbols defined by the cc alone or cpp alone are not in this list, see ccsymbols and cppsymbols. The list is a space-separated list of symbol=value tokens. 🏷️
cppflags — From ccflags.U: …

`cppflags`

This one holds the flags that get passed to the C preprocessor — a whole little bucket of them. And whether they actually get used? That's entirely the Makefile's call, bestie. It's up to the Makefile to use it. 💅

`cpplast`

From cppstdin.U:

Okay so this one's literally the same functionality as cppminus, with one tiny plot twist: it applies to cpprun and not cppstdin. That's it. That's the whole difference. 🎀

`cppminus`

From cppstdin.U:

This one holds the second part of the string that invokes the C preprocessor on standard input and kicks the output over to standard output. Its value is - if cppstdin needs a minus sign to say "hey, standard input," and otherwise the value is "". empty string era. ✨

`cpprun`

From cppstdin.U:

This is the command that invokes a C preprocessor on standard input and puts the output on stdout. It is guaranteed not to be a wrapper, and it may be a null string if no preprocessor can be made directly available. Heads up though — this preprocessor might be a totally different one from the preprocessor your C compiler uses. And do not forget to append cpplast after the preprocessor options. iykyk. 😭

`cppstdin`

From cppstdin.U:

The command that invokes the C preprocessor on standard input and puts the output to stdout. Its main character energy is in being used by other Configure units that ask about preprocessor symbols. 🦋

`cppsymbols`

From Cppsym.U:

Holds the symbols defined by the C preprocessor alone. Symbols defined by cc, or by cc when it calls cpp, are not in this list — for those you want ccsymbols and cppccsymbols. The list is a space-separated list of symbol=value tokens. clean, separated, no mixing. 💜

`crypt_r_proto`

From d_crypt_r.U:

Encodes the prototype of crypt_r. It's zero if d_crypt_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_crypt_r is defined. zero or iconic, no in-between. ⭐

`cryptlib`

From d_crypt.U:

Holds -lcrypt, or the path to a libcrypt.a archive, in the case where the crypt() function isn't defined in the standard C library. Whether it gets used? Makefile's problem, not ours. 💅

`csh`

From Loc.U:

This one's an internal Configure fave — it's used to figure out the full pathname (if any) of the csh program. But after Configure runs, the value gets reset to a plain csh and is not useful anymore. Gone, reduced to atoms. 💀

`ctermid_r_proto`

From d_ctermid_r.U:

Encodes the prototype of ctermid_r. Zero if d_ctermid_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_ctermid_r is defined. 🎀

`ctime_r_proto`

From d_ctime_r.U:

Encodes the prototype of ctime_r. Zero when d_ctime_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h when d_ctime_r is defined. ✨

🌸 d 🌸

okay the d_ section. there are SO many. buckle up bestie, we're going alphabetically and we're going to enjoy it. 🫶

`d_Gconvert`

From d_gconvert.U:

This one holds what Gconvert is defined as, for turning floating point numbers into strings. By default, Configure sets "this" macro to use the first of gconvert, gcvt, or sprintf that pass the sprintf-%g-like behavior tests.

Now — if perl is using long doubles, the macro uses the first of these functions that pass Configure's tests: qgcvt, sprintf (if Configure knows how to make sprintf format long doubles — see sPRIgldbl), gconvert, gcvt, and sprintf (casting to double).

The gconvert_preference and gconvert_ld_preference variables can be used to alter Configure's preferences, for doubles and long doubles respectively. If present, they contain a space-separated list of one or more of the above function names, in the order they should be tried.

And d_Gconvert may be set to override Configure with a platform-specific function. But if that function expects a double, a different value may need to be set by the uselongdouble.cbu call-back unit so that long doubles can be formatted without loss of precision. precision loss is NOT the vibe. 😭

`d_PRIEUldbl`

From longdblfio.U:

Conditionally defines the PERL_PRIfldbl symbol, which indicates that stdio has a symbol to print long doubles. The U in the name is there to separate this from d_PRIeldbl so that even case-blind systems can see the difference. case-blind representation!! 👑

`d_PRIFUldbl`

From longdblfio.U:

Conditionally defines the PERL_PRIfldbl symbol — yes, again — indicating that stdio has a symbol to print long doubles. And the U? It separates this from d_PRIfldbl so even case-blind systems can tell them apart. 🦋

`d_PRIGUldbl`

From longdblfio.U:

Conditionally defines the PERL_PRIfldbl symbol, which indicates stdio has a symbol to print long doubles. The U in the name exists to separate this from d_PRIgldbl so that even case-blind systems can see the difference. ⭐

`d_PRIXU64`

From quadfio.U:

Conditionally defines the PERL_PRIXU64 symbol, which indicates that stdio has a symbol to print 64-bit hExADECimAl numbers. (that capitalization is exactly how it's written, and honestly? iconic.) The U separates this from d_PRIx64 so that even case-blind systems can see the difference. 💜

`d_PRId64`

From quadfio.U:

Conditionally defines the PERL_PRId64 symbol, which indicates that stdio has a symbol to print 64-bit decimal numbers. 🎀

`d_PRIeldbl`

From longdblfio.U:

Conditionally defines the PERL_PRIfldbl symbol, which indicates that stdio has a symbol to print long doubles. 🌸

`d_PRIfldbl`

From longdblfio.U:

Conditionally defines the PERL_PRIfldbl symbol, which indicates stdio has a symbol to print long doubles. the f-squad has arrived. ✨

`d_PRIgldbl`

From longdblfio.U:

Conditionally defines the PERL_PRIfldbl symbol, which indicates that stdio has a symbol to print long doubles. 🫶

`d_PRIi64`

From quadfio.U:

Conditionally defines the PERL_PRIi64 symbol — the one saying stdio has a symbol to print 64-bit decimal numbers. 🦋

`d_PRIo64`

From quadfio.U:

Conditionally defines the PERL_PRIo64 symbol, which indicates that stdio has a symbol to print 64-bit octal numbers. octal girlies rise. 🌈

`d_PRIu64`

From quadfio.U:

Conditionally defines the PERL_PRIu64 symbol, which indicates stdio has a symbol to print 64-bit unsigned decimal numbers. 💅

`d_PRIx64`

From quadfio.U:

Conditionally defines the PERL_PRIx64 symbol, which indicates that stdio has a symbol to print 64-bit hexadecimal numbers. 🔥

`d_SCNfldbl`

From longdblfio.U:

Conditionally defines the PERL_PRIfldbl symbol, which indicates that stdio has a symbol to scan long doubles. scan, not print — totally different assignment. 💖

`d__fwalk`

From d__fwalk.U:

Conditionally defines HAS__FWALK if _fwalk() is available to apply a function to all the file handles. 👑

`d_accept4`

From d_accept4.U:

Conditionally defines HAS_ACCEPT4 if accept4() is available to accept socket connections. 🦋

`d_access`

From d_access.U:

Conditionally defines HAS_ACCESS if the access() system call is available to check for access permissions using real IDs. 🌸

`d_accessx`

From d_accessx.U:

Conditionally defines the HAS_ACCESSX symbol, which tells the C program that the accessx() routine is available. ✨

`d_acosh`

From d_acosh.U:

Conditionally defines the HAS_ACOSH symbol, which indicates to the C program that the acosh() routine is available. math girlies, this is your moment. 💜

`d_aintl`

From d_aintl.U:

Conditionally defines the HAS_AINTL symbol, which indicates to the C program that the aintl() routine is available. And ooh — if copysignl is also present, we can emulate modfl. 🎀

`d_alarm`

From d_alarm.U:

Conditionally defines the HAS_ALARM symbol, which indicates to the C program that the alarm() routine is available. ⏰ wake up bestie.

`d_archlib`

From archlib.U:

Conditionally defines ARCHLIB to hold the pathname of architecture-dependent library files for $package. And if $archlib is the same as $privlib, then this gets set to undef. no duplicate paths on my watch. 💅

`d_asctime64`

From d_timefuncs64.U:

Conditionally defines the HAS_ASCTIME64 symbol, which indicates to the C program that the asctime64 () routine is available. (yes, there's a space before the parens in the original — we keep the lore) 😭

`d_asctime_r`

From d_asctime_r.U:

Conditionally defines the HAS_ASCTIME_R symbol, which indicates to the C program that the asctime_r() routine is available. 🦋

`d_asinh`

From d_asinh.U:

Conditionally defines the HAS_ASINH symbol, which indicates to the C program that the asinh() routine is available. ✨

`d_atanh`

From d_atanh.U:

Conditionally defines the HAS_ATANH symbol, which indicates to the C program that the atanh() routine is available. 🌈

`d_atolf`

From atolf.U:

Conditionally defines the HAS_ATOLF symbol, which indicates to the C program that the atolf() routine is available. 🌸

`d_atoll`

From atoll.U:

Conditionally defines the HAS_ATOLL symbol, which indicates to the C program that the atoll() routine is available. 🫶

`d_attribute_always_inline`

From d_attribut.U:

Conditionally defines HASATTRIBUTE_ALWAYS_INLINE, which indicates that the C compiler can know that certain functions should always be inlined. no takebacks, no maybes. 👑

`d_attribute_deprecated`

From d_attribut.U:

Conditionally defines HASATTRIBUTE_DEPRECATED, which indicates that GCC can handle the attribute for marking deprecated APIs. it's giving "this is so over." 💀

`d_attribute_format`

From d_attribut.U:

Conditionally defines HASATTRIBUTE_FORMAT, which indicates the C compiler can check for printf-like formats. 🎀

`d_attribute_malloc`

From d_attribut.U:

Conditionally defines HASATTRIBUTE_MALLOC, which indicates the C compiler can understand functions as having malloc-like semantics. ✨

`d_attribute_nonnull`

From d_attribut.U:

Conditionally defines HASATTRIBUTE_NONNULL, which indicates that the C compiler can know certain arguments must not be NULL, and will check accordingly at compile time. compile-time catching of nonsense = self care. 💜

`d_attribute_noreturn`

From d_attribut.U:

Conditionally defines HASATTRIBUTE_NORETURN, which indicates that the C compiler can know that certain functions are guaranteed never to return. they leave and they do not come back. 🦋

`d_attribute_pure`

From d_attribut.U:

…

d_attribute_pure — from d_attribut.U: conditionally defines HASATTRIBUTE_PURE, which is the compiler being like "yeah bestie, I know this function is pure" — no side effects, and its results only come from the function input and/or global data. Clean. Predictable. Iconic.
d_attribute_unused — from d_attribut.U: conditionally defines HASATTRIBUTE_UNUSED, which tells you the C compiler can know that certain variables and arguments may not always get used, so it won't throw warnings at you when they don't. She's chill like that 💅
d_attribute_visibility — from d_attribut.U: conditionally defines the HASATTRIBUTE_VISIBILITY symbol, and indicates different "GCC" attribute visibility.
d_attribute_warn_unused_result — from d_attribut.U: conditionally defines HASATTRIBUTE_WARN_UNUSED_RESULT, which means the C compiler can know that certain functions have return values that must not be ignored — think malloc() or open(). Like, please actually look at what I gave you 😭
d_backtrace — from d_backtrace.U: conditionally defines the HAS_BACKTRACE symbol, which tells the C program that the backtrace() routine is available to get a stack trace. Detective mode: activated 🕵️
d_bsd — from Guess.U: conditionally defines the symbol BSD when you're running on a BSD system.
d_bsdgetpgrp — from d_getpgrp.U: conditionally defines USE_BSD_GETPGRP if getpgrp needs one argument, whereas USG one needs none.
d_bsdsetpgrp — from d_setpgrp.U: conditionally defines USE_BSD_SETPGRP if setpgrp needs two arguments, whereas USG one needs none. Also go peek at d_setpgid for a POSIX interface ✨
d_builtin_add_overflow — from d_builtin_overflow.U: conditionally defines HAS_BUILTIN_ADD_OVERFLOW, which means the compiler supports __builtin_add_overflow(x,y,&z) for safely adding x and y into z while checking for overflow. Math but make it safe 🧮
d_builtin_choose_expr — from d_builtin.U: conditionally defines HAS_BUILTIN_CHOOSE_EXPR, which means the compiler supports __builtin_choose_expr(x,y,z). This built-in function is analogous to the x?y:z operator in C, except the expression returned has its type unaltered by promotion rules. Also — and this is the slay part — the built-in function does not evaluate the expression that wasn't chosen. Frugal queen 💅
d_builtin_expect — from d_builtin.U: conditionally defines HAS_BUILTIN_EXPECT, which means the compiler supports __builtin_expect(exp,c). You may use __builtin_expect to provide the compiler with branch prediction information. Giving her a lil heads-up about the future 🔮
d_builtin_mul_overflow — from d_builtin_overflow.U: conditionally defines HAS_BUILTIN_MUL_OVERFLOW, which means the compiler supports __builtin_mul_overflow(x,y,&z) for safely multiplying x and y into z while checking for overflow.
d_builtin_sub_overflow — from d_builtin_overflow.U: conditionally defines HAS_BUILTIN_SUB_OVERFLOW, which means the compiler supports __builtin_sub_overflow(x,y,&z) for safely subtracting y from x into z while checking for overflow. The whole overflow trio is honestly so thoughtful of them 🫶
d_c99_variadic_macros — from d_c99_variadic.U: conditionally defines the HAS_C99_VARIADIC_MACROS symbol, which tells the C program that C99 variadic macros are available. Macros that take however many args you feel like? Obsessed.
d_casti32 — from d_casti32.U: conditionally defines CASTI32, which says whether the C compiler can cast large floats to 32-bit ints.
d_castneg — from d_castneg.U: conditionally defines CASTNEG, which says whether the C compiler can cast negative float to unsigned. Ngl, the answer matters way more than you'd think.
d_cbrt — from d_cbrt.U: conditionally defines the HAS_CBRT symbol, which tells the C program that the cbrt() (cube root) function is available. Cube root bestie, not square root 💀
d_chown — from d_chown.U: conditionally defines the HAS_CHOWN symbol, which tells the C program that the chown() routine is available.
d_chroot — from d_chroot.U: conditionally defines the HAS_CHROOT symbol, which tells the C program that the chroot() routine is available. Changing your whole root, main character energy 👑
d_chsize — from d_chsize.U: conditionally defines the CHSIZE symbol, which tells the C program that the chsize() routine is available to truncate files. Heads up though — you might need a -lx to get this routine. Like, she's not free ✨
d_class — from d_class.U: conditionally defines the HAS_CLASS symbol, which tells the C program that the class() routine is available.
d_clearenv — from d_clearenv.U: conditionally defines the HAS_CLEARENV symbol, which tells the C program that the clearenv () routine is available.
d_closedir — from d_closedir.U: conditionally defines HAS_CLOSEDIR if closedir() is available.
d_cmsghdr_s — from d_cmsghdr_s.U: conditionally defines the HAS_STRUCT_CMSGHDR symbol, which indicates that the struct cmsghdr is supported.
d_copysign — from d_copysign.U: conditionally defines the HAS_COPYSIGN symbol, which tells the C program that the copysign() routine is available.
d_copysignl — from d_copysignl.U: conditionally defines the HAS_COPYSIGNL symbol, which tells the C program that the copysignl() routine is available. And if aintl is also present we can emulate modfl. Look at the teamwork 🫶
d_cplusplus — from d_cplusplus.U: conditionally defines the USE_CPLUSPLUS symbol, which indicates that a C++ compiler was used to compiled Perl and will be used to compile extensions.
d_crypt — from d_crypt.U: conditionally defines the CRYPT symbol, which tells the C program that the crypt() routine is available to encrypt passwords and the like. Secrets and mystery 🔐
d_crypt_r — from d_crypt_r.U: conditionally defines the HAS_CRYPT_R symbol, which tells the C program that the crypt_r() routine is available.
d_csh — from d_csh.U: conditionally defines the CSH symbol, which tells the C program that the C-shell exists. She's out there, living her life.
d_ctermid — from d_ctermid.U: conditionally defines CTERMID if ctermid() is available to generate filename for terminal.
d_ctermid_r — from d_ctermid_r.U: conditionally defines the HAS_CTERMID_R symbol, which tells the C program that the ctermid_r() routine is available.
d_ctime64 — from d_timefuncs64.U: conditionally defines the HAS_CTIME64 symbol, which tells the C program that the ctime64 () routine is available.
d_ctime_r — from d_ctime_r.U: conditionally defines the HAS_CTIME_R symbol, which tells the C program that the ctime_r() routine is available.
d_cuserid — from d_cuserid.U: conditionally defines the HAS_CUSERID symbol, which tells the C program that the cuserid() routine is available to get character login names. Who am I? It's giving existential 💀
d_dbminitproto — from d_dbminitproto.U: conditionally defines the HAS_DBMINIT_PROTO symbol, which tells the C program that the system provides a prototype for the dbminit() function. Otherwise, it's up to the program to supply one. No free prototype, bestie — bring your own.
d_difftime — from d_difftime.U: conditionally defines the HAS_DIFFTIME symbol, which tells the C program that the difftime() routine is available.
d_difftime64 — from d_timefuncs64.U: conditionally defines the HAS_DIFFTIME64 symbol, which tells the C program that the difftime64 () routine is available.
d_dir_dd_fd — from d_dir_dd_fd.U: conditionally defines the HAS_DIR_DD_FD symbol, which indicates that the DIR directory stream type contains a member variable called dd_fd. Sneaky lil member, love that for her.
d_dirfd — from d_dirfd.U: conditionally defines the HAS_DIRFD constant, which tells the C program that dirfd() is available to return the file descriptor of a directory stream.
d_dirnamlen — from i_dirent.U: conditionally defines DIRNAMLEN, which tells the C program that the length of directory entry names is provided by a d_namelen field.
d_dladdr — from d_dladdr.U: conditionally defines the HAS_DLADDR symbol, which tells the C program that the dladdr() routine is available to get a stack trace.
d_dlerror — from d_dlerror.U: conditionally defines the HAS_DLERROR symbol, which tells the C program that the dlerror() routine is available. Something went wrong and now you get to hear about it 😭
d_dlopen — from d_dlopen.U: conditionally defines the HAS_DLOPEN symbol, which tells the C program that the dlopen() routine is available.
d_dlsymun — from d_dlsymun.U: conditionally defines DLSYM_NEEDS_UNDERSCORE, which indicates that we need to prepend an underscore to the symbol name before calling dlsym(). Little underscore, big consequences ✨
d_dosuid — from d_dosuid.U: conditionally defines the symbol DOSUID, which tells the C program that it should insert setuid emulation code on hosts which have setuid #! scripts disabled.
d_double_has_inf — from longdblfio.U: conditionally defines the symbol DOUBLE_HAS_INF which indicates that the double type has an infinity. She goes on forever, honestly 🌈
d_double_has_nan — from longdblfio.U: conditionally defines the symbol DOUBLE_HAS_NAN which indicates that the double type has a not-a-number. Not a number, still a whole vibe 💅
d_double_has_negative_zero — from longdblfio.U: conditionally defines the symbol DOUBLE_HAS_NEGATIVE_ZERO which indicates that the double type has a negative zero. Zero but make it ✨negative✨ — yeah, it's a whole thing.
d_double_has_subnormals — from longdblfio.U: (bestie the sentence keeps going into the next part, we're literally mid-thought here 😭 hold that 🎀)

🌸 `"d_double_style_cray"`

From longdblfio.U:

This one conditionally defines the symbol DOUBLE_STYLE_CRAY, which tells your C program that its double is the 64-bit "CRAY" mainframe format. Mainframe-era double said "I'm built different" and honestly? It was 💅

🦋 `"d_double_style_ibm"`

From longdblfio.U:

Conditionally defines DOUBLE_STYLE_IBM, which signals that double is the 64-bit "IBM" mainframe format. Big blue energy 🟦

🎀 `"d_double_style_ieee"`

From longdblfio.U:

Conditionally defines DOUBLE_STYLE_IEEE, which means your double is the 64-bit "IEEE" 754. The main character of float formats ngl ✨

💜 `"d_double_style_vax"`

From longdblfio.U:

Conditionally defines DOUBLE_STYLE_VAX, telling the program that double is the 64-bit "VAX" format D or G. Vintage icon behavior 👑

🧚 `"d_drand48_r"`

From d_drand48_r.U:

This variable conditionally defines the HAS_DRAND48_R symbol, which lets the C program know that the drand48_r() routine is actually available. Reentrant random go brrr 🎲

⭐ `"d_drand48proto"`

From d_drand48proto.U:

Conditionally defines the HAS_DRAND48_PROTO symbol, which tells the C program that the system ships a prototype for the drand48() function. If it doesn't? Then it's on the program to supply one itself, no cap 🫡

💖 `"d_dup2"`

From d_dup2.U:

Conditionally defines HAS_DUP2 if dup2() is available to duplicate file descriptors. Classic, iconic, dependable 💅

🌈 `"d_dup3"`

From d_dup3.U:

Conditionally defines HAS_DUP3 if dup3() is available to duplicate file descriptors. It's dup2()'s younger sibling and it is serving ✨

🦋 `"d_duplocale"`

From d_newlocale.U:

Conditionally defines the HAS_DUPLOCALE symbol, which tells the C program that the duplocale() routine exists and can duplicate a locale object 🌍

🍓 `"d_eaccess"`

From d_eaccess.U:

Conditionally defines the HAS_EACCESS symbol, which says eaccess() is available. Permission check but make it effective 😌

🎀 `"d_endgrent"`

From d_endgrent.U:

Conditionally defines the HAS_ENDGRENT symbol, which tells the C program that endgrent() is available for sequential access of the group database. Close it out bestie, we're done here 🚪

💜 `"d_endgrent_r"`

From d_endgrent_r.U:

Conditionally defines the HAS_ENDGRENT_R symbol, which means the endgrent_r() routine is available. Same vibe as above, but reentrant ✨

🌸 `"d_endhent"`

From d_endhent.U:

Conditionally defines HAS_ENDHOSTENT if endhostent() is available to close whatever was being used for host queries. Cleanup era 🧹

🧚 `"d_endhostent_r"`

From d_endhostent_r.U:

Conditionally defines the HAS_ENDHOSTENT_R symbol, which indicates the endhostent_r() routine is available 🫶

⭐ `"d_endnent"`

From d_endnent.U:

Conditionally defines HAS_ENDNETENT if endnetent() is available to close whatever was being used for network queries. Leave no query open 💫

🔥 `"d_endnetent_r"`

From d_endnetent_r.U:

Conditionally defines the HAS_ENDNETENT_R symbol, which says endnetent_r() is available 🎀

🦋 `"d_endpent"`

From d_endpent.U:

Conditionally defines HAS_ENDPROTOENT if endprotoent() is available to close whatever was being used for protocol queries. Protocol cleanup, slay 🧼

💖 `"d_endprotoent_r"`

From d_endprotoent_r.U:

Conditionally defines the HAS_ENDPROTOENT_R symbol, which indicates endprotoent_r() is available ✨

🌈 `"d_endpwent"`

From d_endpwent.U:

Conditionally defines the HAS_ENDPWENT symbol, which tells the C program that endpwent() is available for sequential access of the passwd database. Log off of /etc/passwd respectfully 👋

🍓 `"d_endpwent_r"`

From d_endpwent_r.U:

Conditionally defines the HAS_ENDPWENT_R symbol, which means endpwent_r() is available 💅

🎀 `"d_endsent"`

From d_endsent.U:

Conditionally defines HAS_ENDSERVENT if endservent() is available to close whatever was being used for service queries. Service industry closing shift energy 🔔

💜 `"d_endservent_r"`

From d_endservent_r.U:

Conditionally defines the HAS_ENDSERVENT_R symbol, which indicates endservent_r() is available 🫶

🧚 `"d_eofnblk"`

From nblock_io.U:

Conditionally defines EOF_NONBLOCK if EOF can be seen when you're reading from a non-blocking I/O source. Yes bestie, you can still get your end-of-file moment even when nothing's blocking 😭

⭐ `"d_erf"`

From d_erf.U:

Conditionally defines the HAS_ERF symbol, which tells the C program that the erf() routine is available. Error function stans rise 📈

🔥 `"d_erfc"`

From d_erfc.U:

Conditionally defines the HAS_ERFC symbol, which says the erfc() routine is available. The complementary one, obviously 💅

🌸 `"d_eunice"`

From Guess.U:

Conditionally defines the symbols EUNICE and VAX, which alerts the C program that it must deal with the idiosyncrasies of "VMS". Buckle up for the quirks, no cap 💀

🦋 `"d_exp2"`

From d_exp2.U:

Conditionally defines the HAS_EXP2 symbol, which tells the C program that the exp2() routine is available ✨

🎀 `"d_expm1"`

From d_expm1.U:

Conditionally defines the HAS_EXPM1 symbol, which indicates the expm1() routine is available 🎀

💜 `"d_faststdio"`

From d_faststdio.U:

Conditionally defines the HAS_FAST_STDIO symbol, which says the "fast stdio" is available to manipulate the stdio buffers directly. Speed demon behavior, we love to see it 🔥

🍓 `"d_fchdir"`

From d_fchdir.U:

Conditionally defines the HAS_FCHDIR symbol, which indicates the fchdir() routine is available. Change your directory via a file descriptor, iconic 🚪

🌈 `"d_fchmod"`

From d_fchmod.U:

Conditionally defines the HAS_FCHMOD symbol, which tells the C program that fchmod() is available to change the mode of opened files 💅

⭐ `"d_fchmodat"`

From d_fsat.U:

Conditionally defines the HAS_FCHMODAT symbol, which indicates the "POSIX" fchmodat() function is available. The at-suffixed icon ✨

🧚 `"d_fchown"`

From d_fchown.U:

Conditionally defines the HAS_FCHOWN symbol, which tells the C program that fchown() is available to change ownership of opened files. Passing the aux cord, ownership edition 🫶

💖 `"d_fcntl"`

From d_fcntl.U:

Conditionally defines the HAS_FCNTL symbol, and indicates whether the fcntl() function exists at all 🎀

🔥 `"d_fcntl_can_lock"`

From d_fcntl_can_lock.U:

Conditionally defines the FCNTL_CAN_LOCK symbol and indicates whether file locking with fcntl() actually works. Spoiler: sometimes it lowkey doesn't 💀

🦋 `"d_fd_macros"`

From d_fd_set.U:

This variable contains the eventual value of the HAS_FD_MACROS symbol, which indicates if your C compiler knows about the macros that manipulate an fd_set. Note: this one holds a value, it doesn't just toggle a define 👀

🌸 `"d_fd_set"`

From d_fd_set.U:

This variable contains the eventual value of the HAS_FD_SET symbol, which indicates if your C compiler knows about the fd_set typedef ⭐

🎀 `"d_fdclose"`

From d_fdclose.U:

Conditionally defines the HAS_FDCLOSE symbol, which tells the C program that the fdclose() routine is available. Bye bye file descriptor 👋

🍓 `"d_fdim"`

From d_fdim.U:

Conditionally defines the HAS_FDIM symbol, which indicates the fdim() routine is available 💜

🧚 `"d_fdopendir"`

From d_fdopendir.U:

Conditionally defines the HAS_FORK symbol, which indicates that the fdopen routine is available to open a directory descriptor. And yeah — it really does say HAS_FORK in here. We are not the ones who make the rules, bestie 🫠

💖 `"d_fds_bits"`

From d_fd_set.U:

This variable contains the eventual value of the HAS_FDS_BITS symbol, which indicates if your fd_set typedef contains the fds_bits member. And look — if you've got an fd_set typedef but the dweebs who installed it did a half-fast job and neglected to provide the macros to manipulate an fd_set, then HAS_FDS_BITS will let us know how to fix the gaffe. Exposing the flop era of your system headers 😭🔥

🌈 `"d_fegetround"`

From d_fegetround.U:

Conditionally defines HAS_FEGETROUND if fegetround() is available to get the floating point rounding mode. Get that rounding tea ☕

⭐ `"d_ffs"`

From d_ffs.U:

Conditionally defines the HAS_FFS symbol, which tells the C program that ffs() is available to find the first bit which is set in its integer argument. First-bit-finder, main character energy 🔍

🔥 `"d_ffsl"`

From d_ffs.U:

Conditionally defines the HAS_FFSL symbol, which indicates ffsl() is available to find the first bit which is set in its long integer argument. Same quest, bigger int 💪

🦋 `"d_fgetpos"`

From d_fgetpos.U:

Conditionally defines HAS_FGETPOS if fgetpos() is available to get the file position indicator. Where are we in the file? Bestie we're here 📍

🌸 `"d_finite"`

From d_finite.U:

Conditionally defines the HAS_FINITE symbol, which tells the C program that the finite() routine is available. Is your number finite? Vibe check 🌟

🎀 `"d_finitel"`

From d_finitel.U:

Conditionally defines the HAS_FINITEL symbol, which indicates the finitel() routine is available 💅

💜 `"d_flexfnam"`

From d_flexfnam.U:

Conditionally defines the FLEXFILENAMES symbol, which indicates that the system supports filenames longer than 14 characters. Fourteen?! In this economy?! 🗂️😭

🍓 `"d_flock"`

From d_flock.U:

Conditionally defines HAS_FLOCK if flock() is available to do file locking. Lock it down 🔒

🧚 `"d_flockproto"`

From d_flockproto.U:

Conditionally defines the HAS_FLOCK_PROTO symbol, which tells the C program that the system provides a prototype for the flock() function. If it doesn't, it's up to the program to supply one. DIY prototype era 🛠️

⭐ `"d_fma"`

From d_fma.U:

Conditionally defines the HAS_FMA symbol, which indicates the fma() routine is available. Fused multiply-add ate, honestly ✨

🌈 `"d_fmax"`

From d_fmax.U:

Conditionally defines the HAS_FMAX symbol, which tells the C program that the fmax() routine is available. Maximum slay 🌟

🦋 `"d_fmin"`

From d_fmin.U:

…and we're literally mid-sentence here bestie — the description for this one picks up in the next part 💅 (to be continued…)

"d_fmin" — from d_fmin.U:

This one conditionally defines the "HAS_FMIN" symbol, which tells your C program that the fmin() routine is available. 💖

"d_fork" — from d_fork.U:

Conditionally defines "HAS_FORK", which signals to the C program that the fork() routine is available. fork() bestie, the OG process duplicator. 🍴

"d_fp_class" — from d_fp_class.U:

Conditionally defines "HAS_FP_CLASS", which indicates to the C program that the fp_class() routine is available.

"d_fp_classify" — from d_fpclassify.U:

Conditionally defines "HAS_FP_CLASSIFY", which indicates to the C program that the fp_classify() routine is available.

"d_fp_classl" — from d_fp_classl.U:

Conditionally defines "HAS_FP_CLASSL", which indicates to the C program that the fp_classl() routine is available.

"d_fpathconf" — from d_pathconf.U:

Conditionally defines "HAS_FPATHCONF", which indicates to the C program that the pathconf() routine is available to determine file-system related limits and options associated with a given open file descriptor. like, it peeks at the vibes of one specific fd. ✨

"d_fpclass" — from d_fpclass.U:

Conditionally defines "HAS_FPCLASS", which indicates to the C program that the fpclass() routine is available.

"d_fpclassify" — from d_fpclassify.U:

Conditionally defines "HAS_FPCLASSIFY", which indicates to the C program that the fpclassify() routine is available.

"d_fpclassl" — from d_fpclassl.U:

Conditionally defines "HAS_FPCLASSL", which indicates to the C program that the fpclassl() routine is available.

"d_fpgetround" — from d_fpgetround.U:

Conditionally defines "HAS_FPGETROUND" if fpgetround() is available to get the floating point rounding mode. rounding mode gossip fr. 🔥

"d_fpos64_t" — from d_fpos64_t.U:

This symbol will be defined if the C compiler supports fpos64_t. no cap, that's the whole thing. 💅

"d_freelocale" — from d_newlocale.U:

Conditionally defines "HAS_FREELOCALE", which indicates to the C program that the freelocale() routine is available to deallocates the resources associated with a locale object. (yes, that grammar is the original's, we're keeping it 💀)

"d_frexpl" — from d_frexpl.U:

Conditionally defines "HAS_FREXPL", which indicates to the C program that the frexpl() routine is available.

"d_fs_data_s" — from d_fs_data_s.U:

Conditionally defines the "HAS_STRUCT_FS_DATA" symbol, which indicates that the struct fs_data is supported. struct hype 🫶

"d_fseeko" — from d_fseeko.U:

Conditionally defines "HAS_FSEEKO", which indicates to the C program that the fseeko() routine is available.

"d_fsetpos" — from d_fsetpos.U:

Conditionally defines "HAS_FSETPOS" if fsetpos() is available to set the file position indicator.

"d_fstatfs" — from d_fstatfs.U:

Conditionally defines "HAS_FSTATFS", which indicates to the C program that the fstatfs() routine is available.

"d_fstatvfs" — from d_statvfs.U:

Conditionally defines "HAS_FSTATVFS", which indicates to the C program that the fstatvfs() routine is available. note the .U file is d_statvfs.U even though the variable is d_fstatvfs — that's not a typo, that's canon. 🙈

"d_fsync" — from d_fsync.U:

Conditionally defines "HAS_FSYNC", which indicates to the C program that the fsync() routine is available.

"d_ftello" — from d_ftello.U:

Conditionally defines "HAS_FTELLO", which indicates to the C program that the ftello() routine is available.

"d_ftime" — from d_ftime.U:

Conditionally defines "HAS_FTIME", which indicates that the ftime() routine exists. The ftime() routine is basically a sub-second accuracy clock. lowkey niche but iconic. ⭐

"d_futimes" — from d_futimes.U:

Conditionally defines "HAS_FUTIMES", which indicates to the C program that the futimes() routine is available.

"d_gai_strerror" — from d_gai_strerror.U:

Conditionally defines "HAS_GAI_STRERROR" if the gai_strerror() routine is available and can be used to translate error codes returned by getaddrinfo() into human readable strings. it's giving translator bestie for cryptic error codes 😭

"d_gdbm_ndbm_h_uses_prototypes" — from i_ndbm.U:

Conditionally defines the "NDBM_H_USES_PROTOTYPES" symbol, which indicates that the gdbm-ndbm.h include file uses real "ANSI" C prototypes instead of K&R style function declarations. K&R style declarations are unsupported in C++, so the include file requires special handling when using a C++ compiler and this variable is undefined. Consult the different d_*ndbm_h_uses_prototypes variables to get the same information for alternative ndbm.h include files. 👑

"d_gdbmndbm_h_uses_prototypes" — from i_ndbm.U:

Conditionally defines the "NDBM_H_USES_PROTOTYPES" symbol, which indicates that the gdbm/ndbm.h include file uses real "ANSI" C prototypes instead of K&R style function declarations. K&R style declarations are unsupported in C++, so the include file requires special handling when using a C++ compiler and this variable is undefined. Consult the different d_*ndbm_h_uses_prototypes variables to get the same information for alternative ndbm.h include files. (yes bestie, same symbol, different header — read the include file name carefully 💀)

"d_getaddrinfo" — from d_getaddrinfo.U:

Conditionally defines "HAS_GETADDRINFO", which indicates to the C program that the getaddrinfo() function is available.

"d_getcwd" — from d_getcwd.U:

Conditionally defines "HAS_GETCWD", which indicates to the C program that the getcwd() routine is available to get the current working directory. where am i rn energy ✨

"d_getenv_preserves_other_thread" — from d_getenv_thread.U:

Conditionally defines the "GETENV_PRESERVES_OTHER_THREAD" symbol, which indicates to the C program that the getenv() system call does not zap the static buffer in a different thread. thread-safe getenv girlies rise 🫶

"d_getespwnam" — from d_getespwnam.U:

Conditionally defines "HAS_GETESPWNAM" if getespwnam() is available to retrieve enhanced (shadow) password entries by name.

"d_getfsstat" — from d_getfsstat.U:

Conditionally defines "HAS_GETFSSTAT", which indicates to the C program that the getfsstat() routine is available.

"d_getgrent" — from d_getgrent.U:

Conditionally defines "HAS_GETGRENT", which indicates to the C program that the getgrent() routine is available for sequential access of the group database.

"d_getgrent_r" — from d_getgrent_r.U:

Conditionally defines "HAS_GETGRENT_R", which indicates to the C program that the getgrent_r() routine is available. reentrant version, we stan. 💅

"d_getgrgid_r" — from d_getgrgid_r.U:

Conditionally defines "HAS_GETGRGID_R", which indicates to the C program that the getgrgid_r() routine is available.

"d_getgrnam_r" — from d_getgrnam_r.U:

Conditionally defines "HAS_GETGRNAM_R", which indicates to the C program that the getgrnam_r() routine is available.

"d_getgrps" — from d_getgrps.U:

Conditionally defines "HAS_GETGROUPS", which indicates to the C program that the getgroups() routine is available to get the list of process groups.

"d_gethbyaddr" — from d_gethbyad.U:

Conditionally defines "HAS_GETHOSTBYADDR", which indicates to the C program that the gethostbyaddr() routine is available to look up hosts by their "IP" addresses. (and yeah, the .U file is d_gethbyad.U — shorter, iconic, don't question it 🌈)

"d_gethbyname" — from d_gethbynm.U:

Conditionally defines "HAS_GETHOSTBYNAME", which indicates to the C program that the gethostbyname() routine is available to look up host names in some data base or other.

"d_gethent" — from d_gethent.U:

Conditionally defines "HAS_GETHOSTENT" if gethostent() is available to look up host names in some data base or another. "or another" 😭 they said it twice slightly differently, that's a mood.

"d_gethname" — from d_gethname.U:

Conditionally defines "HAS_GETHOSTNAME", which indicates to the C program that the gethostname() routine may be used to derive the host name. may be used. wiggle room. 🎀

"d_gethostbyaddr_r" — from d_gethostbyaddr_r.U:

Conditionally defines "HAS_GETHOSTBYADDR_R", which indicates to the C program that the gethostbyaddr_r() routine is available.

"d_gethostbyname_r" — from d_gethostbyname_r.U:

Conditionally defines "HAS_GETHOSTBYNAME_R", which indicates to the C program that the gethostbyname_r() routine is available.

"d_gethostent_r" — from d_gethostent_r.U:

Conditionally defines "HAS_GETHOSTENT_R", which indicates to the C program that the gethostent_r() routine is available. the whole _r family is eating, ngl. 🔥

"d_gethostprotos" — from d_gethostprotos.U:

Conditionally defines "HAS_GETHOST_PROTOS", which indicates to the C program that <netdb.h> supplies prototypes for the various gethost*() functions. See also netdbtype.U for probing for various netdb types. 👑

"d_getitimer" — from d_getitimer.U:

Conditionally defines "HAS_GETITIMER", which indicates to the C program that the getitimer() routine is available.

"d_getlogin" — from d_getlogin.U:

Conditionally defines "HAS_GETLOGIN", which indicates to the C program that the getlogin() routine is available to get the login name.

"d_getlogin_r" — from d_getlogin_r.U:

Conditionally defines "HAS_GETLOGIN_R", which indicates to the C program that the getlogin_r() routine is available.

"d_getmnt" — from d_getmnt.U:

Conditionally defines "HAS_GETMNT", which indicates to the C program that the getmnt() routine is available to retrieve one or more mount info blocks by filename.

"d_getmntent" — from d_getmntent.U:

`"d_getmntent"`

From d_getmntent.U:

This one conditionally defines the "HAS_GETMNTENT" symbol, bestie, and that's your C program's lil green light saying getmntent() is available to iterate through mounted files and pull their mount info. Slay. ✨

`"d_getnameinfo"`

From d_getnameinfo.U:

Conditionally defines the "HAS_GETNAMEINFO" symbol 🦋 — which is the way your C program finds out that the getnameinfo() function is available. That's it. That's the whole vibe.

`"d_getnbyaddr"`

From d_getnbyad.U:

This one conditionally defines the "HAS_GETNETBYADDR" symbol, telling your C program that the getnetbyaddr() routine is available to look up networks by their "IP" addresses. IP girl behavior fr fr. 💅

`"d_getnbyname"`

From d_getnbynm.U:

Conditionally defines the "HAS_GETNETBYNAME" symbol, which is the little "yes babes, this exists" for your C program — meaning the getnetbyname() routine is available to look up networks by their names. 🌸

`"d_getnent"`

From d_getnent.U:

This variable conditionally defines "HAS_GETNETENT" if getnetent() is available to look up network names in some data base or another. (Yes, "some data base or another" — the manpage is being coy. Iconic of it honestly.) 🙈

`"d_getnetbyaddr_r"`

From d_getnetbyaddr_r.U:

Conditionally defines the "HAS_GETNETBYADDR_R" symbol, which indicates to the C program that the getnetbyaddr_r() routine is available. The _r is giving reentrant queen energy 👑

`"d_getnetbyname_r"`

From d_getnetbyname_r.U:

This one conditionally defines the "HAS_GETNETBYNAME_R" symbol, so your C program knows that the getnetbyname_r() routine is available. Periodt. 🎀

`"d_getnetent_r"`

From d_getnetent_r.U:

Conditionally defines the "HAS_GETNETENT_R" symbol, which indicates to the C program that the getnetent_r() routine is available. Another _r baddie for the collection. ✨

`"d_getnetprotos"`

From d_getnetprotos.U:

This variable conditionally defines the "HAS_GETNET_PROTOS" symbol, which tells your C program that <netdb.h> supplies prototypes for the various getnet*() functions. 👀 Also — slider note — see also netdbtype.U for probing for various netdb types.

`"d_getpagsz"`

From d_getpagsz.U:

This one conditionally defines "HAS_GETPAGESIZE" if getpagesize() is available to get the system page size. Page size girlies rise up 🫶 (and yes, the variable is d_getpagsz while the symbol is HAS_GETPAGESIZE — that's not a typo, that's just how she is)

`"d_getpbyname"`

From d_getprotby.U:

Conditionally defines the "HAS_GETPROTOBYNAME" symbol, which indicates to the C program that the getprotobyname() routine is available to look up protocols by their name. 💖

`"d_getpbynumber"`

From d_getprotby.U:

Same probe file, different mood: this conditionally defines the "HAS_GETPROTOBYNUMBER" symbol, which indicates to the C program that the getprotobynumber() routine is available to look up protocols by their number. Numbers bestie, numbers. 🔢

`"d_getpent"`

From d_getpent.U:

Conditionally defines "HAS_GETPROTOENT" if getprotoent() is available to look up protocols in some data base or another. The "some data base or another" lore continues and honestly? We respect it. 🌈

`"d_getpgid"`

From d_getpgid.U:

Conditionally defines the "HAS_GETPGID" symbol, which indicates to the C program that the getpgid(pid) function is available to get the process group id. Note the pid argument, bestie — copy it exactly, she's specific. 🎀

`"d_getpgrp"`

From d_getpgrp.U:

This variable conditionally defines "HAS_GETPGRP" if getpgrp() is available to get the current process group. Lowkey the more chill sibling of the last one. 💅

`"d_getpgrp2"`

From d_getpgrp2.U:

This one conditionally defines the HAS_GETPGRP2 symbol, which indicates to the C program that the getpgrp2() (as in DG/"UX") routine is available to get the current process group. Keep those quotes around "UX" — that's the archival tea 🫖

`"d_getppid"`

From d_getppid.U:

Conditionally defines the "HAS_GETPPID" symbol, which indicates to the C program that the getppid() routine is available to get the parent process "ID". Parental figure acquired 😭

`"d_getprior"`

From d_getprior.U:

This variable conditionally defines "HAS_GETPRIORITY" if getpriority() is available to get a process's priority. Priorities are real and this function gets them. ⭐

`"d_getprotobyname_r"`

From d_getprotobyname_r.U:

Conditionally defines the "HAS_GETPROTOBYNAME_R" symbol, which indicates to the C program that the getprotobyname_r() routine is available. Reentrant and unbothered. 👑

`"d_getprotobynumber_r"`

From d_getprotobynumber_r.U:

This one conditionally defines the "HAS_GETPROTOBYNUMBER_R" symbol, which indicates to the C program that the getprotobynumber_r() routine is available. Another one for the _r collection, no cap. ✨

`"d_getprotoent_r"`

From d_getprotoent_r.U:

Conditionally defines the "HAS_GETPROTOENT_R" symbol, which indicates to the C program that the getprotoent_r() routine is available. 🦋

`"d_getprotoprotos"`

From d_getprotoprotos.U:

This variable conditionally defines the "HAS_GETPROTO_PROTOS" symbol, which is the heads-up that <netdb.h> supplies prototypes for the various getproto*() functions. 👀 And again: see also netdbtype.U for probing for various netdb types.

`"d_getprpwnam"`

From d_getprpwnam.U:

Conditionally defines "HAS_GETPRPWNAM" if getprpwnam() is available to retrieve protected (shadow) password entries by name. Shadow password entries 🕵️‍♀️ very mysterious very demure.

`"d_getpwent"`

From d_getpwent.U:

This one conditionally defines the "HAS_GETPWENT" symbol, which indicates to the C program that the getpwent() routine is available for sequential access of the passwd database. Sequential access, bestie — one after another, no skipping. 💜

`"d_getpwent_r"`

From d_getpwent_r.U:

Conditionally defines the "HAS_GETPWENT_R" symbol, which indicates to the C program that the getpwent_r() routine is available. 🎀

`"d_getpwnam_r"`

From d_getpwnam_r.U:

This variable conditionally defines the "HAS_GETPWNAM_R" symbol, which indicates to the C program that the getpwnam_r() routine is available. 🌸

`"d_getpwuid_r"`

From d_getpwuid_r.U:

Conditionally defines the "HAS_GETPWUID_R" symbol, which indicates to the C program that the getpwuid_r() routine is available. The passwd trio said "we're all getting _r versions" and honestly? Pop off. ✨

`"d_getsbyname"`

From d_getsrvby.U:

Conditionally defines the "HAS_GETSERVBYNAME" symbol, which indicates to the C program that the getservbyname() routine is available to look up services by their name. 💅

`"d_getsbyport"`

From d_getsrvby.U:

Same probe file, new variable: this conditionally defines the "HAS_GETSERVBYPORT" symbol, which indicates to the C program that the getservbyport() routine is available to look up services by their port. Port girlies, this one's for you 🔥

`"d_getsent"`

From d_getsent.U:

This variable conditionally defines "HAS_GETSERVENT" if getservent() is available to look up network services in some data base or another. Ah, "some data base or another" — we meet again, old friend 😭

`"d_getservbyname_r"`

From d_getservbyname_r.U:

Conditionally defines the "HAS_GETSERVBYNAME_R" symbol, which indicates to the C program that the getservbyname_r() routine is available. 🎀

`"d_getservbyport_r"`

From d_getservbyport_r.U:

This one conditionally defines the "HAS_GETSERVBYPORT_R" symbol, which indicates to the C program that the getservbyport_r() routine is available. 👑

`"d_getservent_r"`

From d_getservent_r.U:

Conditionally defines the "HAS_GETSERVENT_R" symbol, which indicates to the C program that the getservent_r() routine is available. That's three getserv reentrants in a row and they ate. 🫶

`"d_getservprotos"`

From d_getservprotos.U:

This variable conditionally defines the "HAS_GETSERV_PROTOS" symbol, which indicates to the C program that <netdb.h> supplies prototypes for the various getserv*() functions. And — you guessed it — see also netdbtype.U for probing for various netdb types. 🌈

`"d_getspnam"`

From d_getspnam.U:

Conditionally defines "HAS_GETSPNAM" if getspnam() is available to retrieve SysV shadow password entries by name. SysV specifically, bestie — read the label 💅

`"d_getspnam_r"`

From d_getspnam_r.U:

This one conditionally defines the "HAS_GETSPNAM_R" symbol, which indicates to the C program that the getspnam_r() routine is available. ✨

`"d_gettimeod"`

From d_ftime.U:

This variable conditionally defines the "HAS_GETTIMEOFDAY" symbol, which indicates that the gettimeofday() system call exists (to obtain a sub-second accuracy clock). 🕰️ And listen — you should probably include <sys/resource.h>. That's not me being dramatic, that's the page. Include the header. 🙏

`"d_gmtime64"`

From d_timefuncs64.U:

Conditionally defines the HAS_GMTIME64 symbol, which indicates to the C program that the gmtime64 () routine is available. (Yes there's a space before the parens in the original — we keep it exactly, character for character, no cap.) 🎀

`"d_gmtime_r"`

From d_gmtime_r.U:

This variable conditionally defines the "HAS_GMTIME_R" symbol, which indicates to the C program that the gmtime_r() routine is available. 🌸

`"d_gnulibc"`

From d_gnulibc.U:

Defined if we're dealing with the "GNU" C Library. Short, sweet, and glibc-coded 💅

`"d_grpasswd"`

From i_grp.U:

This one conditionally defines "GRPASSWD", which indicates that struct group in <grp.h> contains gr_passwd. Yes the field name is gr_passwd and yes the variable is d_grpasswd — one letter apart, iconic, don't mix them up bestie 🫶

`"d_has_C_UTF8"`

From d_setlocale.U:

This variable is set to either "true" or "false" depending on whether the compilation system supports the C.UTF-8 locale. Not a symbol, an actual value — a whole true/false moment. 🌈

`"d_hasmntopt"`

From d_hasmntopt.U:

Conditionally defines the "HAS_HASMNTOPT" symbol, which indicates to the C program that the hasmntopt() routine is available to query the mount options of file systems. Yes, HAS_HASMNTOPT — the double HAS is real and we love her for it 😭

`"d_htonl"`

From d_htonl.U:

This variable conditionally defines "HAS_HTONL" if htonl() and its friends are available to do network order byte swapping. Endianness besties, this is your moment 🔥

`"d_hypot"`

From d_hypot.U:

Conditionally defines "HAS_HYPOT" if hypot is available for numerically stable hypotenuse function. No parentheses on hypot in the original — that's the exact text, keep it ✨

`"d_ilogb"`

From d_ilogb.U:

This one conditionally defines the "HAS_ILOGB" symbol, which indicates to the C program that the ilogb() routine is available for extracting the exponent of double x as a signed integer. Math girlie behavior 🧮

`"d_ilogbl"`

From d_ilogbl.U:

Conditionally defines the "HAS_ILOGBL" symbol, which indicates to the C program that the ilogbl() routine is available for extracting the exponent of long double x as a signed integer. And plot twist: if scalbnl is also present we can emulate frexpl. Collaboration, not competition 💜

`"d_inc_version_list"`

From inc_version_list.U:

This variable conditionally defines "PERL_INC_VERSION_LIST". It is set to undef when "PERL_INC_VERSION_LIST" is empty. So: defined, but set to undef. She contains multitudes 🫶

`"d_inetaton"`

From d_inetaton.U:

Conditionally defines the "HAS_INET_ATON" symbol, which indicates to the C program that the inet_aton() function is available to parse "IP" address "dotted-quad" strings. Dotted-quad strings, bestie — that's the 192.168.0.1 vibe ✨

`"d_inetntop"`

From d_inetntop.U:

"d_inetntop" — from d_inetntop.U: this one conditionally defines the "HAS_INETNTOP" symbol, which is how your C program finds out that inet_ntop() is available. ✨
"d_inetpton" — from d_inetpton.U: conditionally defines the "HAS_INETPTON" symbol, which tells the C program that inet_pton() is available. (yes bestie the name is d_inetpton, that's not a typo on my end, that's the real one 💅)
"d_int64_t" — from d_int64_t.U: this symbol gets defined if the C compiler supports int64_t.
"d_ip_mreq" — from d_socket.U: conditionally defines the "HAS_IP_MREQ" symbol, which indicates that a struct ip_mreq is available.
"d_ip_mreq_source" — from d_socket.U: conditionally defines the "HAS_IP_MREQ_SOURCE" symbol, which indicates that a struct ip_mreq_source is available.
"d_ipv6_mreq" — from d_socket.U: conditionally defines the HAS_IPV6_MREQ symbol, which indicates that a struct ipv6_mreq is available. 🦋
"d_ipv6_mreq_source" — from d_socket.U: conditionally defines the HAS_IPV6_MREQ_SOURCE symbol, which indicates that a struct ipv6_mreq_source is available.
"d_isascii" — from d_isascii.U: conditionally defines the "HAS_ISASCII" constant, which tells your C program that isascii() is available. 🎀
"d_isblank" — from d_isblank.U: conditionally defines the "HAS_ISBLANK" constant, which tells your C program that isblank() is available.
"d_isfinite" — from d_isfinite.U: conditionally defines the "HAS_ISFINITE" symbol, which indicates that the isfinite() routine is available. 🌸
"d_isfinitel" — from d_isfinitel.U: conditionally defines the "HAS_ISFINITEL" symbol, which indicates that the isfinitel() routine is available.
"d_isinf" — from d_isinf.U: conditionally defines the "HAS_ISINF" symbol, which indicates that the isinf() routine is available.
"d_isinfl" — from d_isinfl.U: conditionally defines the "HAS_ISINFL" symbol, which indicates that the isinfl() routine is available.
"d_isless" — from d_isless.U: conditionally defines the "HAS_ISLESS" symbol, which indicates that the isless() routine is available.
"d_isnan" — from d_isnan.U: conditionally defines the "HAS_ISNAN" symbol, which indicates that the isnan() routine is available. (the classic "is my number not a number" check, iconic 😭)
"d_isnanl" — from d_isnanl.U: conditionally defines the "HAS_ISNANL" symbol, which indicates that the isnanl() routine is available.
"d_isnormal" — from d_isnormal.U: conditionally defines the "HAS_ISNORMAL" symbol, which indicates that the isnormal() routine is available.
"d_j0" — from d_j0.U: conditionally defines the HAS_J0 symbol, which indicates that the j0() routine is available. 🫶
"d_j0l" — from d_j0.U: conditionally defines the HAS_J0L symbol, which indicates that the j0l() routine is available. (same .U file as d_j0, yes, they're roommates 💀)
"d_killpg" — from d_killpg.U: conditionally defines the "HAS_KILLPG" symbol, which indicates that the killpg() routine is available to kill process groups.
"d_lc_monetary_2008" — from d_lc_monetary_2008.U: conditionally defines HAS_LC_MONETARY_2008 if libc has the international currency locale rules from "POSIX" 1003.1-2008. 💸
"d_lchown" — from d_lchown.U: conditionally defines the "HAS_LCHOWN" symbol, which indicates that the lchown() routine is available to operate on a symbolic link (instead of following the link).
"d_ldbl_dig" — from d_ldbl_dig.U: conditionally defines d_ldbl_dig if this system's header files provide "LDBL_DIG", which is the number of significant digits in a long double precision number.
"d_ldexpl" — from d_longdbl.U: conditionally defines the "HAS_LDEXPL" symbol, which indicates that the ldexpl() routine is available.
"d_lgamma" — from d_lgamma.U: conditionally defines the "HAS_LGAMMA" symbol, which indicates that the lgamma() routine is available for the log gamma function. Also peep d_tgamma and d_lgamma_r while you're here. ✨
"d_lgamma_r" — from d_lgamma_r.U: conditionally defines the "HAS_LGAMMA_R" symbol, which indicates that the lgamma_r() routine is available for the log gamma function, without using the global signgam variable. (reentrant queen behavior 👑)
"d_libm_lib_version" — from d_libm_lib_version.U: conditionally defines the "LIBM_LIB_VERSION" symbol, which indicates that math.h defines "_LIB_VERSION" being available in libm.
"d_libname_unique" — from so.U: this variable is defined if the target system insists on unique basenames for shared library files. Currently true on Android, false everywhere else we know of. Defaults to undef.
"d_link" — from d_link.U: conditionally defines "HAS_LINK" if link() is available to create hard links. 🔗
"d_linkat" — from d_fsat.U: conditionally defines the "HAS_LINKAT" symbol, which indicates that the "POSIX" linkat() function is available.
"d_llrint" — from d_llrint.U: conditionally defines the "HAS_LLRINT" symbol, which indicates that the llrint() routine is available to return the long long value closest to a double (according to the current rounding mode).
"d_llrintl" — from d_llrintl.U: conditionally defines the "HAS_LLRINTL" symbol, which indicates that the llrintl() routine is available to return the long long value closest to a long double (according to the current rounding mode).
"d_llround" — from d_llround.U: conditionally defines the "HAS_LLROUND" symbol, which indicates that the llround() routine is available to return the long long value nearest to x.
"d_llroundl" — from d_llroundl.U: conditionally defines the "HAS_LLROUNDL" symbol, which indicates that the llroundl() routine is available to return the long long value nearest to x away from zero.
"d_localeconv_l" — from d_localeconv_l.U: conditionally defines the "HAS_LOCALECONV_L" symbol, which indicates that the localeconv_l() routine is available.
"d_localtime64" — from d_timefuncs64.U: conditionally defines the HAS_LOCALTIME64 symbol, which indicates that the localtime64 () routine is available.
"d_localtime_r" — from d_localtime_r.U: conditionally defines the "HAS_LOCALTIME_R" symbol, which indicates that the localtime_r() routine is available.
"d_localtime_r_needs_tzset" — from d_localtime_r.U: conditionally defines the "LOCALTIME_R_NEEDS_TZSET" symbol, which makes us call tzset before localtime_r(). 🕰️
"d_locconv" — from d_locconv.U: conditionally defines "HAS_LOCALECONV" if localeconv() is available for numeric and monetary formatting conventions.
"d_lockf" — from d_lockf.U: conditionally defines "HAS_LOCKF" if lockf() is available to do file locking. 🔒
"d_log1p" — from d_log1p.U: conditionally defines the HAS_LOG1P symbol, which indicates that the logp1() routine is available to compute log(1 + x) for values of x close to zero. (shoutout to the tiny-x girlies 🍓)
"d_log2" — from d_log2.U: conditionally defines the HAS_LOG2 symbol, which indicates that the log2() routine is available to compute log base two.
"d_logb" — from d_logb.U: conditionally defines the "HAS_LOGB" symbol, which indicates that the logb() routine is available to extract the exponent of x.

"d_long_double_style_ieee" — from d_longdbl.U: conditionally defines "LONG_DOUBLE_STYLE_IEEE" if the long double is any of the "IEEE" 754 style long doubles: "LONG_DOUBLE_STYLE_IEEE_STD", "LONG_DOUBLE_STYLE_IEEE_EXTENDED", "LONG_DOUBLE_STYLE_IEEE_DOUBLEDOUBLE". 🌈
"d_long_double_style_ieee_doubledouble" — from d_longdbl.U: conditionally defines "LONG_DOUBLE_STYLE_IEEE_DOUBLEDOUBLE" if the long double is the 128-bit "IEEE" 754 double-double.
"d_long_double_style_ieee_extended" — from d_longdbl.U: conditionally defines "LONG_DOUBLE_STYLE_IEEE_EXTENDED" if the long double is the 80-bit "IEEE" 754 extended precision. Heads up tho: despite the word "extended", this is actually less than the "std", because this is an extension of the double precision. 🙈
"d_long_double_style_ieee_std" — from d_longdbl.U: conditionally defines "LONG_DOUBLE_STYLE_IEEE_STD" if the long double is the 128-bit "IEEE" 754.
"d_long_double_style_vax" — from d_longdbl.U: conditionally defines "LONG_DOUBLE_STYLE_VAX" if the long double is the 128-bit "VAX" format H.
"d_longdbl" — from d_longdbl.U: conditionally defines "HAS_LONG_DOUBLE" if the long double type is supported.
"d_longlong" — from d_longlong.U: conditionally defines "HAS_LONG_LONG" if the long long type is supported. 💜
"d_lrint" — from d_lrint.U: conditionally defines the "HAS_LRINT" symbol, which indicates that the lrint() routine is available to return the integral value closest to a double (according to the current rounding mode).
"d_lrintl" — from d_lrintl.U: conditionally defines the "HAS_LRINTL" symbol, which indicates that the lrintl() routine is available to return the integral value closest to a long double (according to the current rounding mode).
"d_lround" — from d_lround.U:
"d_lround" — from d_lround.U: conditionally defines the "HAS_LROUND" symbol, which is basically the lil flag that tells your C program "bestie, lround() is here" — it returns the integral value nearest to x. 🎀
"d_lroundl" — from d_lroundl.U: conditionally defines "HAS_LROUNDL", telling your C program that lroundl() is available to return the integral value nearest to x away from zero. slay.
"d_lseekproto" — from d_lseekproto.U: conditionally defines "HAS_LSEEK_PROTO", which says the system hands you a prototype for the lseek() function. If it's not set? Then it's on your program to supply one. no free lunch 💀
"d_lstat" — from d_lstat.U: conditionally defines "HAS_LSTAT" if lstat() is available to do file stats on symbolic links. 🔍
"d_madvise" — from d_madvise.U: conditionally defines "HAS_MADVISE" if madvise() is available to map a file into memory.
"d_malloc_good_size" — from d_malloc_size.U: this symbol, if defined, indicates the malloc_good_size routine is available for use. ✨
"d_malloc_size" — from d_malloc_size.U: this symbol, if defined, indicates the malloc_size routine is available for use.
"d_malloc_usable_size" — from d_malloc_size.U: this symbol, if defined, indicates the malloc_usable_size routine is available for use.
"d_mblen" — from d_mblen.U: conditionally defines "HAS_MBLEN", which tells your C program mblen() exists to find the number of bytes in a multibyte character. 🦋
"d_mbrlen" — from d_mbrlen.U: conditionally defines "HAS_MBRLEN" if mbrlen() is available — it gets you the length of multi-byte character strings.
"d_mbrtowc" — from d_mbrtowc.U: conditionally defines "HAS_MBRTOWC" if mbrtowc() is available, used to convert a multi-byte character into a wide character. 💜
"d_mbstowcs" — from d_mbstowcs.U: conditionally defines "HAS_MBSTOWCS", telling your C program mbstowcs() is around to convert a multibyte string into a wide character string.
"d_mbtowc" — from d_mbtowc.U: conditionally defines "HAS_MBTOWC", which says mbtowc() is available to convert multibyte to a wide character.
"d_memmem" — from d_memmem.U: conditionally defines "HAS_MEMMEM", so your C program knows memmem() is available to return a pointer to the start of the first occurrence of a substring in a memory area — or "NULL" if it's not found. 🫶
"d_memrchr" — from d_memrchr.U: conditionally defines "HAS_MEMRCHR", which says memrchr() is available to return a pointer to the last occurrence of a byte in a memory area (or "NULL" if not found).
"d_mkdir" — from d_mkdir.U: conditionally defines "HAS_MKDIR", telling your C program mkdir() is available to create directories.. 🎀 (yes, directories, we're building a whole lil home for your files)
"d_mkdtemp" — from d_mkdtemp.U: conditionally defines "HAS_MKDTEMP", which says mkdtemp() is available to exclusively create a uniquely named temporary directory. it's giving safe and sound.
"d_mkfifo" — from d_mkfifo.U: conditionally defines "HAS_MKFIFO", indicating mkfifo() is available. iconic pipe behaviour tbh.
"d_mkostemp" — from d_mkostemp.U: conditionally defines "HAS_MKOSTEMP" if mkostemp() is available to exclusively create and open a uniquely named (with a suffix) temporary file. 🔥
"d_mkstemp" — from d_mkstemp.U: conditionally defines "HAS_MKSTEMP", telling your C program mkstemp() is available to exclusively create and open a uniquely named temporary file.
"d_mkstemps" — from d_mkstemps.U: conditionally defines "HAS_MKSTEMPS", which says mkstemps() is here to exclusively create and open a uniquely named (with a suffix) temporary file. 💅
"d_mktime" — from d_mktime.U: conditionally defines "HAS_MKTIME", indicating mktime() is available. timezone girlie stuff, yk.
"d_mktime64" — from d_timefuncs64.U: conditionally defines the HAS_MKTIME64 symbol, which tells your C program the mktime64 () routine is available. ⭐
"d_mmap" — from d_mmap.U: conditionally defines "HAS_MMAP" if mmap() is available to map a file into memory. main character syscall fr fr.
"d_modfl" — from d_modfl.U: conditionally defines "HAS_MODFL", which says modfl() is available. floats doing float things ✨
"d_modflproto" — from d_modfl.U: this symbol, if defined, indicates the system provides a prototype for the modfl() function. otherwise it's up to the program to supply one. and heads up: C99 says it should be long double modfl(long double, long double *); — write it like that, no cap. 📝
"d_mprotect" — from d_mprotect.U: conditionally defines "HAS_MPROTECT" if mprotect() is available to modify the access protection of a memory mapped file. 🔐
"d_msg" — from d_msg.U: conditionally defines "HAS_MSG", which indicates the entire msg*(2) library is present. the whole squad showed up 🫶
"d_msg_ctrunc" — from d_socket.U: conditionally defines "HAS_MSG_CTRUNC", which indicates "MSG_CTRUNC" is available. and bestie, #ifdef is not enough here because it may be an enum — glibc has been known to do this. 💀
"d_msg_dontroute" — from d_socket.U: conditionally defines "HAS_MSG_DONTROUTE", which indicates "MSG_DONTROUTE" is available. again: #ifdef is not enough, it may be an enum, glibc has been known to do this. 🙈
"d_msg_oob" — from d_socket.U: conditionally defines "HAS_MSG_OOB", which indicates "MSG_OOB" is available. same warning, same reason — #ifdef is not enough because it may be an enum, glibc has been known to do this.
"d_msg_peek" — from d_socket.U: conditionally defines "HAS_MSG_PEEK", which indicates "MSG_PEEK" is available. and yup — #ifdef is not enough because it may be an enum, glibc has been known to do this. 👀
"d_msg_proxy" — from d_socket.U: conditionally defines "HAS_MSG_PROXY", which indicates "MSG_PROXY" is available. one more time for the people in the back: #ifdef is not enough because it may be an enum, glibc has been known to do this. 🎀
"d_msgctl" — from d_msgctl.U: conditionally defines "HAS_MSGCTL", which tells your C program the msgctl() routine is available.
"d_msgget" — from d_msgget.U: conditionally defines "HAS_MSGGET", indicating msgget() is available.
"d_msghdr_s" — from d_msghdr_s.U: conditionally defines "HAS_STRUCT_MSGHDR", which indicates the struct msghdr is supported. 🦋
"d_msgrcv" — from d_msgrcv.U: conditionally defines "HAS_MSGRCV", telling your C program msgrcv() is available.
"d_msgsnd" — from d_msgsnd.U: conditionally defines "HAS_MSGSND", indicating msgsnd() is available. sending messages, receiving messages, we stay communicating 💌
"d_msync" — from d_msync.U: conditionally defines "HAS_MSYNC" if msync() is available to synchronize a mapped file.
"d_munmap" — from d_munmap.U: conditionally defines "HAS_MUNMAP" if munmap() is available to unmap a region mapped by mmap(). clean up after yourself bestie 🧹
"d_mymalloc" — from mallocsrc.U: conditionally defines "MYMALLOC" in case other parts of the source want to take special action if "MYMALLOC" is used. that can include different sorts of profiling or error detection — lowkey multipurpose. ✨
"d_nan" — from d_nan.U: conditionally defines "HAS_NAN" if nan() is available to generate NaN. not a number but very much a vibe 🌸
"d_nanosleep" — from d_nanosleep.U: conditionally defines "HAS_NANOSLEEP" if nanosleep() is available to sleep with 1E-9 sec accuracy. beauty sleep, but make it precise 💅
"d_ndbm" — from i_ndbm.U: conditionally defines "HAS_NDBM", which indicates that both the ndbm.h include file and an appropriate ndbm library exist. consult the different i_*ndbm variables to find out the actual include location. sometimes a system has the header file but not the library — messy — and this variable will only be set if the system has both. 💀
"d_ndbm_h_uses_prototypes" — from i_ndbm.U: conditionally defines the "NDBM_H_USES_PROTOTYPES" symbol, which indicates the ndbm.h include file uses real "ANSI" C prototypes instead of K&R style function declarations. and here's the tea: K&R style declarations are unsupported in C++, so the include file requires special handling when using a C++ compiler and this variable is undefined. 🫶 consult the different d_*ndbm_h_uses_prototypes variables to get the same information for alternative ndbm.h include files.
"d_nearbyint" — from d_nearbyint.U: conditionally defines "HAS_NEARBYINT" if nearbyint() is available to return the integral value closest to (according to the current rounding mode) to x. ⭐
"d_newlocale" — from d_newlocale.U: conditionally defines "HAS_NEWLOCALE", which tells your C program newlocale() is available to return a new locale object or modify an existing locale object. glow-up for your locale 🌈
"d_nextafter" — from d_nextafter.U: conditionally defines "HAS_NEXTAFTER" if nextafter() is available to return the next machine representable double from x in direction y. one tiny step at a time, bestie 👑

`d_nexttoward`

From d_nexttoward.U:

bestie this one conditionally defines HAS_NEXTTOWARD when nexttoward() is available — it returns the next machine representable long double from x in direction y. literally one tiny step through the float grid ✨

`d_nice`

From d_nice.U:

conditionally defines the HAS_NICE symbol, which tells your C program that the nice() routine is available. be nice to your processes, they're doing their best 🫶

`d_nl_langinfo`

From d_nl_langinfo.U:

conditionally defines the HAS_NL_LANGINFO symbol, which tells your C program that the nl_langinfo() routine is available. locale info queen 👑

`d_nl_langinfo_l`

From d_nl_langinfo.U:

conditionally defines the HAS_NL_LANGINFO_L symbol, which tells your C program that the nl_langinfo_l() routine is available. yes the _l one, she's the locale-aware variant, slay 💅

`d_non_int_bitfields`

From d_bitfield.U:

this variable conditionally defines HAS_NON_INT_BITFIELDS, which indicates that the C compiler accepts struct bitfields of sizes that aren't int or unsigned int. your compiler being flexible fr fr 🦋

`d_nv_preserves_uv`

From perlxv.U:

this variable indicates whether a variable of type nvtype can preserve all the bits a variable of type uvtype has. no lost bits, no cap 💖

`d_nv_zero_is_allbits_zero`

From perlxv.U:

this variable indicates whether a variable of type nvtype stores 0.0 in memory as all bits zero. a zero that's actually all zeroes, iconic ⭐

`d_off64_t`

From d_off64_t.U:

this symbol will be defined if the C compiler supports off64_t.

`d_old_pthread_create_joinable`

From d_pthrattrj.U:

this variable conditionally defines pthread_create_joinable. it's undef if pthread.h defines PTHREAD_CREATE_JOINABLE. 💀 gotta check both sides of that one

`d_oldpthreads`

From usethreads.U:

this variable conditionally defines the OLD_PTHREADS_API symbol, and indicates that Perl should be built to use the old draft POSIX threads API.

heads up: this is only potentially meaningful if usethreads is set. like, context matters bb 🙈

`d_oldsock`

From d_socket.U:

this variable conditionally defines the OLDSOCKET symbol, which indicates that the BSD socket interface is based on 4.1c and not 4.2. vintage. antique even 🎀

`d_open3`

From d_open3.U:

this variable conditionally defines the HAS_OPEN3 manifest constant, which tells your C program that the 3 argument version of the open(2) function is available. three-arg open my beloved ✨

`d_openat`

From d_fsat.U:

this variable conditionally defines the HAS_OPENAT symbol, which indicates the POSIX openat() function is available.

`d_pathconf`

From d_pathconf.U:

this variable conditionally defines the HAS_PATHCONF symbol, which tells your C program that the pathconf() routine is available to determine file-system related limits and options associated with a given filename. she knows your filesystem's boundaries 🌸

`d_pause`

From d_pause.U:

this variable conditionally defines the HAS_PAUSE symbol, which tells your C program that the pause() routine is available to suspend a process until a signal is received. nap time until someone pings you 😭

`d_perl_lc_all_category_positions_init`

From disparate_lc_all.U:

this symbol, if defined, indicates that $lc_all_category_positions_init is valid.

`d_perl_lc_all_separator`

From disparate_lc_all.U:

this symbol, if defined, indicates that $perl_lc_all_separator is valid.

`d_perl_lc_all_uses_name_value_pairs`

From disparate_lc_all.U:

this symbol, if defined, indicates that the string returned by setlocale("LC_ALL", "NULL") uses "name=value;" pairs to indicate what each category's locale is when they aren't all set to the same locale.

when it's not defined, the platform uses positional notation instead. two whole different ways of saying the same thing, iykyk 🔥

`d_perl_otherlibdirs`

From otherlibdirs.U:

this variable conditionally defines PERL_OTHERLIBDIRS, which contains a colon-separated set of paths for the perl binary to include in @INC. see also otherlibdirs. 🧚

`d_phostname`

From d_gethname.U:

this variable conditionally defines the HAS_PHOSTNAME symbol, which contains the shell command which, when fed to popen(), may be used to derive the host name. shell command as a value, chaotic but it works 💜

`d_pipe`

From d_pipe.U:

this variable conditionally defines the HAS_PIPE symbol, which tells your C program that the pipe() routine is available to create an inter-process channel. talk to each other besties 🫶

`d_pipe2`

From d_pipe2.U:

this variable conditionally defines the HAS_PIPE2 symbol, which tells your C program that the pipe2() routine is available to create an inter-process channel. pipe but make it extra ✨

`d_poll`

From d_poll.U:

this variable conditionally defines the HAS_POLL symbol, which tells your C program that the poll() routine is available to poll active file descriptors. she's just checking in on everyone 🌈

`d_portable`

From d_portable.U:

this variable conditionally defines the PORTABLE symbol, which tells your C program that it should not assume that it's running on the machine it was compiled on.

no cap, that's the whole vibe: expect to be a guest somewhere else 🦋

`d_prctl`

From d_prctl.U:

this variable conditionally defines the HAS_PRCTL symbol, which tells your C program that the prctl() routine is available.

warning bestie: there are at least two prctl variants — Linux and Irix. while they're somewhat similar, they're incompatible. do not mix them up 😭

`d_prctl_set_name`

From d_prctl.U:

this variable conditionally defines the HAS_PRCTL_SET_NAME symbol, which tells your C program that the prctl() routine supports the PR_SET_NAME option. naming your threads, main character energy 👑

`d_printf_format_null`

From d_attribut.U:

this variable conditionally defines PRINTF_FORMAT_NULL_OK, which indicates the C compiler allows printf-like formats to be null.

`d_procselfexe`

From d_procselfexe.U:

defined if $procselfexe is symlink to the absolute pathname of the executing program.

`d_pseudofork`

From d_vfork.U:

this variable conditionally defines the HAS_PSEUDOFORK symbol, which indicates that an emulation of the fork routine is available. not the real thing, but she's doing her best 💅

`d_pthread_atfork`

From d_pthread_atfork.U:

this variable conditionally defines the HAS_PTHREAD_ATFORK symbol, which tells your C program that the pthread_atfork() routine is available.

`d_pthread_attr_setscope`

From d_pthread_attr_ss.U:

this variable conditionally defines HAS_PTHREAD_ATTR_SETSCOPE if pthread_attr_setscope() is available to set the contention scope attribute of a thread attribute object. very specific, very valid ⭐

`d_pthread_yield`

From d_pthread_y.U:

this variable conditionally defines the HAS_PTHREAD_YIELD symbol if the pthread_yield routine is available to yield the execution of the current thread. share the floor bestie 🫶

`d_ptrdiff_t`

From d_ptrdiff_t.U:

this symbol will be defined if the C compiler supports ptrdiff_t.

`d_pwage`

From i_pwd.U:

this variable conditionally defines PWAGE, which indicates that struct passwd contains pw_age.

`d_pwchange`

From i_pwd.U:

this variable conditionally defines PWCHANGE, which indicates that struct passwd contains pw_change.

`d_pwclass`

From i_pwd.U:

this variable conditionally defines PWCLASS, which indicates that struct passwd contains pw_class.

`d_pwcomment`

From i_pwd.U:

this variable conditionally defines PWCOMMENT, which indicates that struct passwd contains pw_comment.

`d_pwexpire`

From i_pwd.U:

this variable conditionally defines PWEXPIRE, which indicates that struct passwd contains pw_expire.

`d_pwgecos`

From i_pwd.U:

this variable conditionally defines PWGECOS, which indicates that struct passwd contains pw_gecos.

`d_pwpasswd`

From i_pwd.U:

this variable conditionally defines PWPASSWD, which indicates that struct passwd contains pw_passwd.

`d_pwquota`

From i_pwd.U:

this variable conditionally defines PWQUOTA, which indicates that struct passwd contains pw_quota.

yes the whole struct passwd extended-field tour is here, we're getting through all of them, no skipping 💀

`d_qgcvt`

From d_qgcvt.U:

this variable conditionally defines the HAS_QGCVT symbol, which tells your C program that the qgcvt() routine is available.

`d_quad`

From quadtype.U:

this variable, if defined, tells that there's a 64-bit integer type, quadtype. big number szn 🔥

`d_querylocale`

From d_newlocale.U:

this variable conditionally defines the HAS_QUERYLOCALE symbol, which tells your C program that the querylocale() routine is available to return the name of the locale for a category mask. asking the locale who she is 💅

`d_random_r`

From d_random_r.U:

this variable conditionally defines the HAS_RANDOM_R symbol, which tells your C program that the random_r() routine is available.

`d_re_comp`

From d_regcmp.U:

this variable conditionally defines the HAS_RECOMP symbol, which tells your C program that the re_comp() routine is available for regular pattern matching (usually on BSD). if so, it's likely that re_exec() exists too. package deal 🎀

`d_readdir`

From d_readdir.U:

this variable conditionally defines HAS_READDIR if readdir() is available to read directory entries.

`d_readdir64_r`

From d_readdir64_r.U:

this variable conditionally defines the HAS_READDIR64_R symbol, which tells your C program that the readdir64_r() routine is available.

`d_readdir_r`

From d_readdir_r.U:

this variable conditionally defines the HAS_READDIR_R symbol, which tells your C program that the readdir_r() routine is available.

`d_readlink`

From d_readlink.U:

this variable conditionally defines the HAS_READLINK symbol, which tells your C program that the readlink() routine is available to read the value of a symbolic link. peeking behind the symlink curtain 🌸

`d_readv`

From d_readv.U:

this variable conditionally defines the HAS_READV symbol, which tells your C program that the readv() routine is available.

`d_recvmsg`

From d_recvmsg.U:

this variable conditionally defines the HAS_RECVMSG symbol, which tells your C program that the recvmsg() routine is available.

`d_regcmp`

From d_regcmp.U:

this variable conditionally defines the HAS_REGCMP symbol, which tells your C program that the regcmp() routine is available for regular pattern matching (usually on System V). 🦋

`d_regcomp`

From d_regcmp.U:

"d_regcomp" — from d_regcomp.U — conditionally defines the HAS_REGCOMP symbol, which tells your C program that the regcomp() routine is available for regular pattern matching (usually on POSIX.2 conforming systems). regex girlies, this one's for you 💅
"d_remainder" — from d_remainder.U — conditionally defines the HAS_REMAINDER symbol, which tells your C program that the remainder() routine is available. math slay ✨
"d_remquo" — from d_remquo.U — conditionally defines the HAS_REMQUO symbol, which tells your C program that the remquo() routine is available.
"d_rename" — from d_rename.U — conditionally defines the HAS_RENAME symbol, which tells your C program that rename() is available to rename files. glow-up for your filenames 🦋
"d_renameat" — from d_fsat.U — conditionally defines the HAS_RENAMEAT symbol, which indicates the "POSIX" renameat() function is available.
"d_rewinddir" — from d_readdir.U — conditionally defines HAS_REWINDDIR if rewinddir() is available. rewind, bestie, it's not that deep 😭
"d_rint" — from d_rint.U — conditionally defines the HAS_RINT symbol, which tells your C program that the rint() routine is available.
"d_rmdir" — from d_rmdir.U — conditionally defines HAS_RMDIR if rmdir() is available to remove directories. bye-bye directory 👋
"d_round" — from d_round.U — conditionally defines the HAS_ROUND symbol, which tells your C program that the round() routine is available.
"d_sbrkproto" — from d_sbrkproto.U — conditionally defines the HAS_SBRK_PROTO symbol, which tells your C program that the system provides a prototype for the sbrk() function. Otherwise, it's up to the program to supply one. no prototype? then you're on your own, girl 🙈
"d_scalbn" — from d_scalbn.U — conditionally defines the HAS_SCALBN symbol, which tells your C program that the scalbn() routine is available.
"d_scalbnl" — from d_scalbnl.U — conditionally defines the HAS_SCALBNL symbol, which tells your C program that the scalbnl() routine is available. If ilogbl is also present we can emulate frexpl. combo move 🔥
"d_sched_yield" — from d_pthread_y.U — conditionally defines the HAS_SCHED_YIELD symbol if the sched_yield routine is available to yield the execution of the current thread. share the CPU, it's giving generosity ✨
"d_scm_rights" — from d_socket.U — conditionally defines the HAS_SCM_RIGHTS symbol, which indicates that the "SCM_RIGHTS" is available. #ifdef is not enough because it may be an enum, glibc has been known to do this. glibc being chaotic, as per usual 💀
"d_seekdir" — from d_readdir.U — conditionally defines HAS_SEEKDIR if seekdir() is available. seeking, but make it directory 📂
"d_select" — from d_select.U — conditionally defines HAS_SELECT if select() is available to select active file descriptors. A <sys/time.h> inclusion may be necessary for the timeout field. heads up, fr fr ⭐
"d_sem" — from d_sem.U — conditionally defines the HAS_SEM symbol, which indicates that the entire sem*(2) library is present. the whole collection, not just a single 🎀
"d_semctl" — from d_semctl.U — conditionally defines the HAS_SEMCTL symbol, which tells your C program that the semctl() routine is available.
"d_semctl_semid_ds" — from d_union_semun.U — conditionally defines USE_SEMCTL_SEMID_DS, which indicates that struct semid_ds * is to be used for semctl "IPC_STAT". struct girlies rise 👑
"d_semctl_semun" — from d_union_semun.U — conditionally defines USE_SEMCTL_SEMUN, which indicates that union semun is to be used for semctl "IPC_STAT". union girlies, your moment 🫶
"d_semget" — from d_semget.U — conditionally defines the HAS_SEMGET symbol, which tells your C program that the semget() routine is available.
"d_semop" — from d_semop.U — conditionally defines the HAS_SEMOP symbol, which tells your C program that the semop() routine is available.
"d_sendmsg" — from d_sendmsg.U — conditionally defines the HAS_SENDMSG symbol, which tells your C program that the sendmsg() routine is available. sliding into the socket's DMs 💌
"d_setegid" — from d_setegid.U — conditionally defines the HAS_SETEGID symbol, which tells your C program that the setegid() routine is available to change the effective gid of the current program.
"d_setenv" — from d_setenv.U — conditionally defines the HAS_SETENV symbol, which tells your C program that the setenv routine is available. setting env vars, main character behaviour 🌈
"d_seteuid" — from d_seteuid.U — conditionally defines the HAS_SETEUID symbol, which tells your C program that the seteuid() routine is available to change the effective uid of the current program.
"d_setgrent" — from d_setgrent.U — conditionally defines the HAS_SETGRENT symbol, which tells your C program that the setgrent() routine is available for initializing sequential access to the group database. group chat, but a database 💅
"d_setgrent_r" — from d_setgrent_r.U — conditionally defines the HAS_SETGRENT_R symbol, which tells your C program that the setgrent_r() routine is available. the reentrant version, she's got range ✨
"d_setgrps" — from d_setgrps.U — conditionally defines the HAS_SETGROUPS symbol, which tells your C program that the setgroups() routine is available to set the list of process groups. plural, bestie, a whole list of them 🎀
"d_sethent" — from d_sethent.U — conditionally defines HAS_SETHOSTENT if sethostent() is available.
"d_sethostent_r" — from d_sethostent_r.U — conditionally defines the HAS_SETHOSTENT_R symbol, which tells your C program that the sethostent_r() routine is available.
"d_setitimer" — from d_setitimer.U — conditionally defines the HAS_SETITIMER symbol, which tells your C program that the setitimer() routine is available. timers going off, very demure ⏰
"d_setlinebuf" — from d_setlnbuf.U — conditionally defines the HAS_SETLINEBUF symbol, which tells your C program that the setlinebuf() routine is available to change stderr or stdout from block-buffered or unbuffered to a line-buffered mode. buffering glow-up 😌
"d_setlocale" — from d_setlocale.U — conditionally defines HAS_SETLOCALE if setlocale() is available to handle locale-specific ctype implementations. going international 🌍
"d_setlocale_accepts_any_locale_name" — from d_setlocale.U — conditionally defines SETLOCALE_ACCEPTS_ANY_LOCALE_NAME if setlocale() accepts any locale name. no gatekeeping on the locale names 💜
"d_setlocale_r" — from d_setlocale_r.U — conditionally defines the HAS_SETLOCALE_R symbol, which tells your C program that the setlocale_r() routine is available.
"d_setnent" — from d_setnent.U — conditionally defines HAS_SETNETENT if setnetent() is available.
"d_setnetent_r" — from d_setnetent_r.U — conditionally defines the HAS_SETNETENT_R symbol, which tells your C program that the setnetent_r() routine is available.
"d_setpent" — from d_setpent.U — conditionally defines HAS_SETPROTOENT if setprotoent() is available. yes, the variable is d_setpent and the symbol is HAS_SETPROTOENT, don't come for me, that's just how it is 🙈
"d_setpgid" — from d_setpgid.U — conditionally defines the HAS_SETPGID symbol if the setpgid(pid, gpid) function is available to set process group "ID". keep that argument order exactly as written, king 🫶
"d_setpgrp" — from d_setpgrp.U — conditionally defines HAS_SETPGRP if setpgrp() is available to set the current process group.
"d_setpgrp2" — from d_setpgrp2.U — conditionally defines the HAS_SETPGRP2 symbol, which tells your C program that the setpgrp2() (as in DG/"UX") routine is available to set the current process group. the sequel nobody expected 🍓
"d_setprior" — from d_setprior.U — conditionally defines HAS_SETPRIORITY if setpriority() is available to set a process's priority. priorities, we have them 👑
"d_setproctitle" — from d_setproctitle.U — conditionally defines the HAS_SETPROCTITLE symbol, which tells your C program that the setproctitle() routine is available.
"d_setprotoent_r" — from d_setprotoent_r.U — conditionally defines the HAS_SETPROTOENT_R symbol, which tells your C program that the setprotoent_r() routine is available.
"d_setpwent" — from d_setpwent.U — conditionally defines the HAS_SETPWENT symbol, which tells your C program that the setpwent() routine is available for initializing sequential access to the passwd database. passwd database walk-through, one entry at a time ✨
"d_setpwent_r" — from d_setpwent_r.U — conditionally defines the HAS_SETPWENT_R symbol, which tells your C program that the setpwent_r() routine is available.
"d_setregid" — from d_setregid.U — conditionally defines HAS_SETREGID if setregid() is available to change the real and effective gid of the current process. two gids, one call 💅
"d_setresgid" — from d_setregid.U — conditionally defines HAS_SETRESGID if setresgid() is available to change the real, effective and saved gid of the current process. three gids now, she's levelling up 🌸
"d_setresuid" — from d_setreuid.U — conditionally defines HAS_SETREUID if setresuid() is available to change the real, effective and saved uid of the current process. yes, the symbol really is HAS_SETREUID here — not my typo, I promise, write it down exactly like this 😭
"d_setreuid" — from d_setreuid.U — conditionally defines HAS_SETREUID if setreuid() is available to change the real and effective uid of the current process.
"d_setrgid" — from d_setrgid.U — conditionally defines the HAS_SETRGID symbol, which tells your C program that the setrgid() routine is available to change the real gid of the current program.
"d_setruid" — from d_setruid.U — conditionally defines the HAS_SETRUID symbol, which tells your C program that the setruid() routine is available to change the real uid of the current program.
"d_setsent" — from d_setsent.U —

okay and that's genuinely where this part cuts off, bestie — d_setsent's description is picking up in the next chunk, so don't leave yet 🫶

Finishing off d_setservent: this variable conditionally defines "HAS_SETSERVENT" if setservent() is available. Slay. 💖 Now bestie, here’s the rest of this variable block — every d_* check, every fact intact, zero missing details. 🫶

"d_setservent_r" — from d_setservent_r.U: this variable conditionally defines the "HAS_SETSERVENT_R" symbol, which tells your C program that the setservent_r() routine is available. ✨
"d_setsid" — from d_setsid.U: this variable conditionally defines "HAS_SETSID" if setsid() is available to set the process group "ID". 💅
"d_setvbuf" — from d_setvbuf.U: this variable conditionally defines the "HAS_SETVBUF" symbol, which tells your C program that the setvbuf() routine is available to change buffering on an open stdio stream. 🎀
"d_shm" — from d_shm.U: this variable conditionally defines the "HAS_SHM" symbol, which indicates that the entire shm*(2) library is present. 👑
"d_shmat" — from d_shmat.U: this variable conditionally defines the "HAS_SHMAT" symbol, which tells your C program that the shmat() routine is available. 🦋
"d_shmatprototype" — from d_shmat.U: this variable conditionally defines the "HAS_SHMAT_PROTOTYPE" symbol, which indicates that sys/shm.h has a prototype for shmat. 🌸
"d_shmctl" — from d_shmctl.U: this variable conditionally defines the "HAS_SHMCTL" symbol, which tells your C program that the shmctl() routine is available. 💖
"d_shmdt" — from d_shmdt.U: this variable conditionally defines the "HAS_SHMDT" symbol, which tells your C program that the shmdt() routine is available. ✨
"d_shmget" — from d_shmget.U: this variable conditionally defines the "HAS_SHMGET" symbol, which tells your C program that the shmget() routine is available. 🫶
"d_sigaction" — from d_sigaction.U: this variable conditionally defines the "HAS_SIGACTION" symbol, which indicates that the Vr4 sigaction() routine is available. 🔥
"d_siginfo_si_addr" — from d_siginfo_si.U: this variable conditionally defines the "HAS_SIGINFO_SI_ADDR" symbol, which indicates that the siginfo_t struct has the si_addr member. 💅
"d_siginfo_si_band" — from d_siginfo_si.U: this variable conditionally defines the "HAS_SIGINFO_SI_BAND" symbol, which indicates that the siginfo_t struct has the si_band member. 🌈
"d_siginfo_si_errno" — from d_siginfo_si.U: this variable conditionally defines the "HAS_SIGINFO_SI_ERRNO" symbol, which indicates that the siginfo_t struct has the si_errno member. 💜
"d_siginfo_si_fd" — from d_siginfo_si.U: this variable conditionally defines the "HAS_SIGINFO_SI_FD" symbol, which indicates that the siginfo_t struct has the si_fd member. 🍓
"d_siginfo_si_pid" — from d_siginfo_si.U: this variable conditionally defines the "HAS_SIGINFO_SI_PID" symbol, which indicates that the siginfo_t struct has the si_pid member. 🧚
"d_siginfo_si_status" — from d_siginfo_si.U: this variable conditionally defines the "HAS_SIGINFO_SI_STATUS" symbol, which indicates that the siginfo_t struct has the si_status member. ⭐
"d_siginfo_si_uid" — from d_siginfo_si.U: this variable conditionally defines the "HAS_SIGINFO_SI_UID" symbol, which indicates that the siginfo_t struct has the si_uid member. 💖
"d_siginfo_si_value" — from d_siginfo_si.U: this variable conditionally defines the "HAS_SIGINFO_SI_VALUE" symbol, which indicates that the siginfo_t struct has the si_value member. 🦋
"d_signbit" — from d_signbit.U: this variable conditionally defines the "HAS_SIGNBIT" symbol, which tells your C program that the signbit() routine is available and safe to use with perl’s intern "NV" type. 😭
"d_sigprocmask" — from d_sigprocmask.U: this variable conditionally defines "HAS_SIGPROCMASK" if sigprocmask() is available to examine or change the signal mask of the calling process. 🔥
"d_sigsetjmp" — from d_sigsetjmp.U: this variable conditionally defines the "HAS_SIGSETJMP" symbol, which indicates that the sigsetjmp() routine is available to call setjmp() and optionally save the process’s signal mask. 👑
"d_sin6_scope_id" — from d_socket.U: this variable conditionally defines the HAS_SIN6_SCOPE_ID symbol, which indicates that a struct sockaddr_in6 structure has the sin6_scope_id member. 🌸
"d_sitearch" — from sitearch.U: this variable conditionally defines "SITEARCH" to hold the pathname of architecture-dependent library files for $package. If $sitearch is the same as $archlib, then this is set to undef. 🎀
"d_snprintf" — from d_snprintf.U: this variable conditionally defines the "HAS_SNPRINTF" symbol, which tells your C program that the snprintf () library function is available. ✨
"d_sockaddr_in6" — from d_socket.U: this variable conditionally defines the HAS_SOCKADDR_IN6 symbol, which indicates the availability of a struct sockaddr_in6. 💅
"d_sockaddr_sa_len" — from d_socket.U: this variable conditionally defines the "HAS_SOCKADDR_SA_LEN" symbol, which indicates that a struct sockaddr structure has the sa_len member. 🌈
"d_sockaddr_storage" — from d_socket.U: this variable conditionally defines the "HAS_SOCKADDR_STORAGE" symbol, which indicates the availability of a struct sockaddr_storage. 💜
"d_sockatmark" — from d_sockatmark.U: this variable conditionally defines the "HAS_SOCKATMARK" symbol, which tells your C program that the sockatmark() routine is available. 🍓
"d_sockatmarkproto" — from d_sockatmarkproto.U: this variable conditionally defines the "HAS_SOCKATMARK_PROTO" symbol, which tells your C program that the system provides a prototype for the sockatmark() function. Otherwise, it is up to the program to supply one. 🧚
"d_socket" — from d_socket.U: this variable conditionally defines "HAS_SOCKET", which indicates that the "BSD" socket interface is supported. ⭐
"d_socklen_t" — from d_socklen_t.U: this symbol will be defined if the C compiler supports socklen_t. 💖
"d_sockpair" — from d_socket.U: this variable conditionally defines the "HAS_SOCKETPAIR" symbol, which indicates that the "BSD" socketpair() is supported. 🦋
"d_socks5_init" — from d_socks5_init.U: this variable conditionally defines the HAS_SOCKS5_INIT symbol, which tells your C program that the socks5_init() routine is available. 😭
"d_sqrtl" — from d_sqrtl.U: this variable conditionally defines the "HAS_SQRTL" symbol, which tells your C program that the sqrtl() routine is available. 🔥
"d_srand48_r" — from d_srand48_r.U: this variable conditionally defines the HAS_SRAND48_R symbol, which tells your C program that the srand48_r() routine is available. 👑
"d_srandom_r" — from d_srandom_r.U: this variable conditionally defines the "HAS_SRANDOM_R" symbol, which tells your C program that the srandom_r() routine is available. 🌸
"d_sresgproto" — from d_sresgproto.U: this variable conditionally defines the "HAS_SETRESGID_PROTO" symbol, which tells your C program that the system provides a prototype for the setresgid() function. Otherwise, it is up to the program to supply one. 🎀
"d_sresuproto" — from d_sresuproto.U: this variable conditionally defines the "HAS_SETRESUID_PROTO" symbol, which tells your C program that the system provides a prototype for the setresuid() function. Otherwise, it is up to the program to supply one. ✨
"d_stat" — from d_stat.U: this variable conditionally defines "HAS_STAT" if stat() is available to get file status. 💅
"d_statblks" — from d_statblks.U: this variable conditionally defines "USE_STAT_BLOCKS" if this system has a stat structure declaring st_blksize and st_blocks. 🌈
"d_statfs_f_flags" — from d_statfs_f_flags.U: this variable conditionally defines the "HAS_STRUCT_STATFS_F_FLAGS" symbol, which indicates that struct statfs from has the f_flags member. This kind of struct statfs is coming from sys/mount.h ("BSD"), not from sys/statfs.h ("SYSV"). 💜
"d_statfs_s" — from d_statfs_s.U: this variable conditionally defines the "HAS_STRUCT_STATFS" symbol, which indicates that the struct statfs is supported. 🍓
"d_static_inline" — from d_static_inline.U: this variable conditionally defines the "HAS_STATIC_INLINE" symbol, which indicates that the C compiler supports C99-style static inline. That is, the function can’t be called from another translation unit. 🧚
"d_statvfs" — from d_statvfs.U: this variable conditionally defines the "HAS_STATVFS" symbol, which tells your C program that the statvfs() routine is available. ⭐
"d_stdio_cnt_lval" — from d_stdstdio.U: this variable conditionally defines "STDIO_CNT_LVALUE" if the "FILE_cnt" macro can be used as an lvalue. 💖
"d_stdio_ptr_lval" — from d_stdstdio.U: this variable conditionally defines "STDIO_PTR_LVALUE" if the "FILE_ptr" macro can be used as an lvalue. 🦋
"d_stdio_ptr_lval_nochange_cnt" — from d_stdstdio.U: this symbol is defined if using the "FILE_ptr" macro as an lvalue to increase the pointer by n leaves File_cnt(fp) unchanged. 😭
"d_stdio_ptr_lval_sets_cnt" — from d_stdstdio.U: this symbol is defined if using the "FILE_ptr" macro as an lvalue to increase the pointer by n has the side effect of decreasing the value of File_cnt(fp) by n. 🔥
"d_stdio_stream_array" — from stdio_streams.U: this variable tells whether there is an array holding the stdio streams. 👑
"d_stdiobase" — from d_stdstdio.U: this variable conditionally defines "USE_STDIO_BASE" if this system has a "FILE" structure declaring a usable _base field (or equivalent) in stdio.h. 🌸
"d_stdstdio" — from d_stdstdio.U: this variable conditionally defines "USE_STDIO_PTR" if this system has a "FILE" structure declaring usable _ptr and _cnt fields (or equivalent) in stdio.h. 🎀
"d_strcoll" — from d_strcoll.U: this variable conditionally defines "HAS_STRCOLL" if strcoll() is available to compare strings using collating information. ✨
"d_strerror_l" — from d_strerror_l.U:

...and the C program can find out if it can call the strerror_l() routine to grab the error message for a given errno value in a particular locale (the locale is identified by a locale_t object, iykyk). ✨

`"d_strerror_r"`

From d_strerror_r.U:

This variable conditionally defines the "HAS_STRERROR_R" symbol, which tells the C program that yes bestie, the strerror_r() routine is available. 🫶

`"d_strftime"`

From d_strftime.U:

This variable conditionally defines the "HAS_STRFTIME" symbol, which indicates to the C program that the strftime() routine is available. formatting time like it's nothing 💅

`"d_strlcat"`

From d_strlcat.U:

This variable conditionally defines the "HAS_STRLCAT" symbol, which indicates to the C program that the strlcat () routine is available.

`"d_strlcpy"`

From d_strlcpy.U:

This variable conditionally defines the "HAS_STRLCPY" symbol, which indicates to the C program that the strlcpy () routine is available.

`"d_strnlen"`

From d_strnlen.U:

This variable conditionally defines the "HAS_STRNLEN" symbol, which indicates to the C program that the strnlen () routine is available.

`"d_strtod"`

From d_strtod.U:

This variable conditionally defines the "HAS_STRTOD" symbol, which indicates to the C program that the strtod() routine is available — and it gives you better numeric string conversion than atof(). glow-up fr fr 🔥

`"d_strtod_l"`

From d_strtod_l.U:

This variable conditionally defines the "HAS_STRTOD_L" symbol, which indicates to the C program that the strtod_l() routine is available.

`"d_strtol"`

From d_strtol.U:

This variable conditionally defines the "HAS_STRTOL" symbol, which indicates to the C program that the strtol() routine is available to provide better numeric string conversion than atoi() and friends. sorry atoi(), it's giving flop era 💀

`"d_strtold"`

From d_strtold.U:

This variable conditionally defines the "HAS_STRTOLD" symbol, which indicates to the C program that the strtold() routine is available.

`"d_strtold_l"`

From d_strtold_l.U:

This variable conditionally defines the "HAS_STRTOLD_L" symbol, which indicates to the C program that the strtold_l() routine is available.

`"d_strtoll"`

From d_strtoll.U:

This variable conditionally defines the "HAS_STRTOLL" symbol, which indicates to the C program that the strtoll() routine is available.

`"d_strtoq"`

From d_strtoq.U:

This variable conditionally defines the "HAS_STRTOQ" symbol, which indicates to the C program that the strtoq() routine is available.

`"d_strtoul"`

From d_strtoul.U:

This variable conditionally defines the "HAS_STRTOUL" symbol, which indicates to the C program that the strtoul() routine is available to provide conversion of strings to unsigned long. 💜

`"d_strtoull"`

From d_strtoull.U:

This variable conditionally defines the "HAS_STRTOULL" symbol, which indicates to the C program that the strtoull() routine is available.

`"d_strtouq"`

From d_strtouq.U:

This variable conditionally defines the "HAS_STRTOUQ" symbol, which indicates to the C program that the strtouq() routine is available.

`"d_strxfrm"`

From d_strxfrm.U:

This variable conditionally defines "HAS_STRXFRM" if strxfrm() is available to transform strings. transforming ✨

`"d_strxfrm_l"`

From d_strxfrm_l.U:

This variable conditionally defines "HAS_STRXFRM_L" if strxfrm_l() is available to transform strings.

`"d_suidsafe"`

From d_dosuid.U:

This variable conditionally defines "SETUID_SCRIPTS_ARE_SECURE_NOW" if setuid scripts can be secure. 🔐 This test looks in /dev/fd/.

`"d_symlink"`

From d_symlink.U:

This variable conditionally defines the "HAS_SYMLINK" symbol, which indicates to the C program that the symlink() routine is available to create symbolic links. linking things to other things, main character behaviour 🦋

`"d_syscall"`

From d_syscall.U:

This variable conditionally defines "HAS_SYSCALL" if syscall() is available call arbitrary system calls.

`"d_syscallproto"`

From d_syscallproto.U:

This variable conditionally defines the "HAS_SYSCALL_PROTO" symbol, which indicates to the C program that the system provides a prototype for the syscall() function. Otherwise, it's up to the program to supply one. no prototype? guess you're DIY-ing it 😭

`"d_sysconf"`

From d_sysconf.U:

This variable conditionally defines the "HAS_SYSCONF" symbol, which indicates to the C program that the sysconf() routine is available to determine system related limits and options.

`"d_sysernlst"`

From d_strerror.U:

This variable conditionally defines "HAS_SYS_ERRNOLIST" if sys_errnolist[] is available to translate error numbers to the symbolic name.

`"d_syserrlst"`

From d_strerror.U:

This variable conditionally defines "HAS_SYS_ERRLIST" if sys_errlist[] is available to translate error numbers to strings.

`"d_system"`

From d_system.U:

This variable conditionally defines "HAS_SYSTEM" if system() is available to issue a shell command. 🐚

`"d_tcgetpgrp"`

From d_tcgtpgrp.U:

This variable conditionally defines the "HAS_TCGETPGRP" symbol, which indicates to the C program that the tcgetpgrp() routine is available. to get foreground process group "ID".

`"d_tcsetpgrp"`

From d_tcstpgrp.U:

This variable conditionally defines the "HAS_TCSETPGRP" symbol, which indicates to the C program that the tcsetpgrp() routine is available to set foreground process group "ID".

`"d_telldir"`

From d_readdir.U:

This variable conditionally defines "HAS_TELLDIR" if telldir() is available.

`"d_telldirproto"`

From d_telldirproto.U:

This variable conditionally defines the "HAS_TELLDIR_PROTO" symbol, which indicates to the C program that the system provides a prototype for the telldir() function. Otherwise, it's up to the program to supply one.

`"d_tgamma"`

From d_tgamma.U:

This variable conditionally defines the "HAS_TGAMMA" symbol, which indicates to the C program that the tgamma() routine is available for the gamma function. See also d_lgamma. 🧮

`"d_thread_local"`

From d_thread_local.U:

This variable conditionally defines the "PERL_THREAD_LOCAL" symbol. In turn that gives a linkage specification for thread-local storage.

`"d_time"`

From d_time.U:

This variable conditionally defines the "HAS_TIME" symbol, which indicates that the time() routine exists. The time() routine is normally provided on "UNIX" systems. ⏰

`"d_timegm"`

From d_timegm.U:

This variable conditionally defines the "HAS_TIMEGM" symbol, which indicates to the C program that the timegm () routine is available.

`"d_times"`

From d_times.U:

This variable conditionally defines the "HAS_TIMES" symbol, which indicates that the times() routine exists. The times() routine is normally provided on "UNIX" systems. You may have to include <sys/times.h>.

`"d_tm_tm_gmtoff"`

From i_time.U:

This variable conditionally defines "HAS_TM_TM_GMTOFF", which indicates to the C program that the struct tm has the tm_gmtoff field.

`"d_tm_tm_zone"`

From i_time.U:

This variable conditionally defines "HAS_TM_TM_ZONE", which indicates to the C program that the struct tm has the tm_zone field.

`"d_tmpnam_r"`

From d_tmpnam_r.U:

This variable conditionally defines the "HAS_TMPNAM_R" symbol, which indicates to the C program that the tmpnam_r() routine is available.

`"d_towlower"`

From d_towlower.U:

This variable conditionally defines the "HAS_TOWLOWER" symbol, which indicates to the C program that the towlower() routine is available.

`"d_towupper"`

From d_towupper.U:

This variable conditionally defines the "HAS_TOWUPPER" symbol, which indicates to the C program that the towupper() routine is available.

`"d_trunc"`

From d_trunc.U:

This variable conditionally defines the "HAS_TRUNC" symbol, which indicates to the C program that the trunc() routine is available to round doubles towards zero.

`"d_truncate"`

From d_truncate.U:

This variable conditionally defines "HAS_TRUNCATE" if truncate() is available to truncate files. ✂️

`"d_truncl"`

From d_truncl.U:

This variable conditionally defines the "HAS_TRUNCL" symbol, which indicates to the C program that the truncl() routine is available to round long doubles towards zero. If copysignl is also present, we can emulate modfl. the way that combo pops off 🔥

`"d_ttyname_r"`

From d_ttyname_r.U:

This variable conditionally defines the "HAS_TTYNAME_R" symbol, which indicates to the C program that the ttyname_r() routine is available.

`"d_tzname"`

From d_tzname.U:

This variable conditionally defines "HAS_TZNAME" if tzname[] is available to access timezone names. 🌍

`"d_u32align"`

From d_u32align.U:

This variable tells whether you must access character data through U32-aligned pointers. alignment check bestie 🎀

`"d_ualarm"`

From d_ualarm.U:

This variable conditionally defines the "HAS_UALARM" symbol, which indicates to the C program that the ualarm() routine is available.

`"d_umask"`

From d_umask.U:

This variable conditionally defines the "HAS_UMASK" symbol, which indicates to the C program that the umask() routine is available. to set and get the value of the file creation mask.

`"d_uname"`

From d_gethname.U:

This variable conditionally defines the "HAS_UNAME" symbol, which indicates to the C program that the uname() routine may be used to derive the host name.

`"d_union_semun"`

From d_union_semun.U:

This variable conditionally defines "HAS_UNION_SEMUN" if the union semun is defined by including <sys/sem.h>.

`"d_unlinkat"`

From d_fsat.U:

This variable conditionally defines the "HAS_UNLINKAT" symbol, which indicates the "POSIX" unlinkat() function isavailable.

`"d_unordered"`

From d_unordered.U:

This variable conditionally defines the "HAS_UNORDERED" symbol, which indicates to the C program that the unordered() routine is available.

`"d_unsetenv"`

From d_unsetenv.U:

This variable conditionally defines the "HAS_UNSETENV" symbol, which indicates to the C program that the unsetenv () routine is available.

`"d_uselocale"`

From d_newlocale.U:

"d_uselocale" — from d_uselocale.U: conditionally defines the "HAS_USELOCALE" symbol, which tells your C program that the uselocale() routine is available to set the current locale for the calling thread. thread-specific locale?? we love to see it 💅
"d_usleep" — from d_usleep.U: conditionally defines "HAS_USLEEP" if usleep() is available to do high granularity sleeps. tiny little beauty naps for your process 😴✨
"d_usleepproto" — from d_usleepproto.U: conditionally defines the "HAS_USLEEP_PROTO" symbol, which tells the C program that the system provides a prototype for the usleep() function. and if it doesn't? then it's up to the program to supply one. no cap 🙈
"d_ustat" — from d_ustat.U: conditionally defines "HAS_USTAT" if ustat() is available to query file system statistics by dev_t. file system stats, slay 🍓
"d_vendorarch" — from vendorarch.U: conditionally defined "PERL_VENDORARCH". (yes bestie, defined — that's what it says 🙈)
"d_vendorbin" — from vendorbin.U: conditionally defines "PERL_VENDORBIN". 💖
"d_vendorlib" — from vendorlib.U: conditionally defines "PERL_VENDORLIB". 📚
"d_vendorscript" — from vendorscript.U: conditionally defines "PERL_VENDORSCRIPT". 📜
"d_vfork" — from d_vfork.U: conditionally defines the "HAS_VFORK" symbol, which indicates the vfork() routine is available. ✨
"d_void_closedir" — from d_closedir.U: conditionally defines "VOID_CLOSEDIR" if closedir() does not return a value. void mood, honestly 💀
"d_voidsig" — from d_voidsig.U: conditionally defines "VOIDSIG" if this system declares "void (*signal(...))()" in signal.h. the old way was to declare it as "int (*signal(...))()". glow-up fr 🔥
"d_voidtty" — from i_sysioctl.U: conditionally defines "USE_IOCNOTTY" to indicate that the ioctl() call with "TIOCNOTTY" should be used to void tty association. otherwise (on "USG" probably), it is enough to close the standard file descriptors and do a setpgrp(). bye tty 👋
"d_vsnprintf" — from d_snprintf.U: conditionally defines the "HAS_VSNPRINTF" symbol, which indicates to the C program that the vsnprintf () library function is available. (yes with the little space before the parens, that's the original ✨)
"d_wait4" — from d_wait4.U: conditionally defines the HAS_WAIT4 symbol, which indicates the wait4() routine is available.
"d_waitpid" — from d_waitpid.U: conditionally defines "HAS_WAITPID" if waitpid() is available to wait for child process. waiting for the kids to come home 😭
"d_wcrtomb" — from d_wcrtomb.U: conditionally defines the "HAS_WCRTOMB" symbol if the wcrtomb() routine is available to be used to convert a wide character into a multi-byte character. wide to multibyte, we love a conversion 💅
"d_wcscmp" — from d_wcscmp.U: conditionally defines the "HAS_WCSCMP" symbol if the wcscmp() routine is available and can be used to compare wide character strings. comparison slay ✨
"d_wcstombs" — from d_wcstombs.U: conditionally defines the "HAS_WCSTOMBS" symbol, which indicates to the C program that the wcstombs() routine is available to convert wide character strings to multibyte strings.
"d_wcsxfrm" — from d_wcsxfrm.U: conditionally defines the "HAS_WCSXFRM" symbol if the wcsxfrm() routine is available and can be used to compare wide character strings.
"d_wctomb" — from d_wctomb.U: conditionally defines the "HAS_WCTOMB" symbol, which indicates to the C program that the wctomb() routine is available to convert a wide character to a multibyte.
"d_writev" — from d_writev.U: conditionally defines the "HAS_WRITEV" symbol, which indicates to the C program that the writev() routine is available.
"d_xenix" — from Guess.U: conditionally defines the symbol "XENIX", which alerts the C program that it runs under Xenix. blast from the past 🦋
"date" — from Loc.U: used internally by Configure to determine the full pathname (if any) of the date program. after Configure runs, the value is reset to a plain "date" and is not useful. so like... don't rely on it after, noted 🙈
"db_hashtype" — from i_db.U: contains the type of the hash structure element in the <db.h> header file. in older versions of "DB" it was int, while in newer ones it is u_int32_t. glow-up 💅
"db_prefixtype" — from i_db.U: contains the type of the prefix structure element in the <db.h> header file. in older versions of "DB" it was int, while in newer ones it is size_t.
"db_version_major" — from i_db.U: contains the major version number of Berkeley "DB" found in the <db.h> header file.
"db_version_minor" — from i_db.U: contains the minor version number of Berkeley "DB" found in the <db.h> header file. for "DB" version 1 this is always 0.
"db_version_patch" — from i_db.U: contains the patch version number of Berkeley "DB" found in the <db.h> header file. for "DB" version 1 this is always 0.
"default_inc_excludes_dot" — from defaultincdot.U: when defined, remove the legacy . from @"INC". the dot had to go 🫶
"direntrytype" — from i_dirent.U: this symbol is set to "struct direct" or "struct dirent" depending on whether dirent is available or not. use this pseudo type to portably declare your directory entries. portability queen 👑
"dlext" — from dlext.U: contains the extension that is to be used for the dynamically loaded modules that perl generates.
"dlsrc" — from dlsrc.U: contains the name of the dynamic loading file that will be used with the package.
"doubleinfbytes" — from infnan.U: contains comma-separated list of hexadecimal bytes for the double precision infinity. infinity but make it bytes ✨
"doublekind" — from longdblfio.U: if defined, encodes the type of a double:
- 1 = "IEEE" 754 32-bit little endian
- 2 = "IEEE" 754 32-bit big endian
- 3 = "IEEE" 754 64-bit little endian
- 4 = "IEEE" 754 64-bit big endian
- 5 = "IEEE" 754 128-bit little endian
- 6 = "IEEE" 754 128-bit big endian
- 7 = "IEEE" 754 64-bit mixed endian le-be
- 8 = "IEEE" 754 64-bit mixed endian be-le
- 9 = "VAX" 32bit little endian F float format
- 10 = "VAX" 64bit little endian D float format
- 11 = "VAX" 64bit little endian G float format
- 12 = "IBM" 32bit format
- 13 = "IBM" 64bit format
- 14 = Cray 64bit format
- -1 = unknown format
"doublemantbits" — from mantbits.U: this symbol, if defined, tells how many mantissa bits there are in double precision floating point format. note that this is usually "DBL_MANT_DIG" minus one, since with the standard "IEEE" 754 formats "DBL_MANT_DIG" includes the implicit bit which doesn't really exist. sneaky implicit bit 🙈
"doublenanbytes" — from infnan.U: contains comma-separated list of hexadecimal bytes for the double precision not-a-number. NaN but in bytes, iconic 🍓
"doublesize" — from doublesize.U: contains the value of the "DOUBLESIZE" symbol, which indicates to the C program how many bytes there are in a double.
"drand01" — from randfunc.U: indicates the macro to be used to generate normalized random numbers. uses randfunc, often divided by (double) (((unsigned long) 1 << randbits)) in order to normalize the result. in C programs, the macro "Drand01" is mapped to drand01. random but normalized 💅
"drand48_r_proto" — from d_drand48_r.U: encodes the prototype of drand48_r. it is zero if d_drand48_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_drand48_r is defined.
"dtrace" — from usedtrace.U: holds the location of the dtrace executable.
"dtraceobject" — from dtraceobject.U: whether we need to build an object file with the dtrace tool.
"dtracexnolibs" — from dtraceobject.U: whether dtrace accepts -xnolibs. if available we call dtrace -h and dtrace -G with -xnolibs to allow dtrace to run in a jail on FreeBSD. freeBSD jail but make it cute 🦋
"dynamic_ext" — from Extensions.U: holds a list of "XS" extension files we want to link dynamically into the package. it is used by Makefile. Makefile stays winning 🫶

🦋 e 🦋

"eagain" — from nblock_io.U: bears the symbolic errno code set by read() when no data is present on the file and non-blocking I/O was enabled (otherwise, read() blocks naturally). bestie said "no data? not today" 😭
"ebcdic" — from ebcdic.U: conditionally defines "EBCDIC" if this system uses "EBCDIC" encoding.
"echo" — from Loc.U: used internally by Configure to determine the full pathname (if any) of the echo program. after Configure runs, the value is reset to a plain "echo" and is not useful.
"egrep" — from Loc.U: used internally by Configure to determine the full pathname (if any) of the egrep program. after Configure runs, the value is reset to a plain "egrep" and is not useful.
"emacs" — from Loc.U: this variable is defined but not used by Configure. the value is the empty string and is not useful. so it's literally just vibes 💀
"endgrent_r_proto" — from d_endgrent_r.U: encodes the prototype of endgrent_r. it is zero if d_endgrent_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_endgrent_r is defined.
"endhostent_r_proto" — from d_endhostent_r.U: encodes the prototype of endhostent_r. it is zero if d_endhostent_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_endhostent_r is defined.
"endnetent_r_proto" — from d_endnetent_r.U: encodes the prototype of endnetent_r. it is zero if d_endnetent_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_endnetent_r is defined.
"endprotoent_r_proto" — from d_endprotoent_r.U: encodes the prototype of endprotoent_r. it is zero if d_endprotoent_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_endprotoent_r is defined.
"endpwent_r_proto" — from d_endpwent_r.U: encodes the prototype of endpwent_r. it is zero if d_endpwent_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_endpwent_r is defined.
"endservent_r_proto" — from d_endservent_r.U: this one encodes the prototype of endservent_r. It's zero if d_endservent_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_endservent_r is defined. 💅
"eunicefix" — from Init.U: when you're running under Eunice, this variable holds a command that converts a shell script into the proper form of text file so the shell can actually execute it. On every other system? It's a no-op. literally does nothing, iconic honestly 🎀
"exe_ext" — from Unix.U: bestie this is just an old synonym for _exe. that's it. that's the whole thing ✨
"expr" — from Loc.U: used internally by Configure to figure out the full pathname (if any) of the expr program. After Configure runs, the value gets reset to a plain "expr" and is genuinely not useful anymore. so don't come for it 🙈
"extensions" — from Extensions.U: holds a list of all the extension files (both "XS" and non-xs) installed with the package. It gets propagated to Config.pm and is typically used to test whether a particular extension is available. she's a checklist girlie 🦋
"extern_C" — from Csym.U: "ANSI" C requires extern where C++ requires 'extern "C"'. This variable lets Configure do the right thing in both worlds. bilingual queen 👑
"extras" — from Extras.U: holds a list of extra modules to install. extra. on brand 💖

f 🌸

"fflushNULL" — from fflushall.U: if this symbol is defined, it means fflush("NULL") correctly flushes all pending stdio output with no side effects. But ⚠️ on some platforms calling fflush("NULL") still corrupts "STDIN" if it's a pipe. so like… defined means safe, but the footnote is scary, iykyk 💀
"fflushall" — from fflushall.U: if this symbol is defined, it means that to flush all pending stdio output you have to loop through all the stdio file handles stored in an array and fflush each one yourself. manual labour era 😭. and note: if fflushNULL is defined, fflushall won't even be probed for and gets left undefined. they don't overlap, periodt.
"find" — from Loc.U: this variable is literally defined but not used by Configure. The value is the empty string and is not useful. she's just vibing, contributing nothing 🫶
"firstmakefile" — from Unix.U: defines the first file searched by make. On unix it's makefile (then Makefile). On case-insensitive systems it might be something else entirely. Only used to deal with convoluted make depend tricks — and it absolutely earns that "convoluted" title 🌀
"flex" — from Loc.U: defined but not used by Configure. Value is the empty string, not useful. matching set with find, love that for them ✨
"fpossize" — from fpossize.U: contains the size of a fpostype, in bytes. measuring tape out 📏
"fpostype" — from fpostype.U: defines Fpos_t to be something like fpos_t, long, uint, or whatever type the libc uses to declare file positions. mystery type, but we respect her 🌈
"freetype" — from mallocsrc.U: contains the return type of free(). Usually void, but occasionally int — those platforms woke up and chose chaos 💀
"from" — from Cross.U: contains the command Configure uses to copy files from the target host. Useful and available only during the Perl build. The string ":" if not cross-compiling. so the colon is the "nope, not doing that" flag 😌
"full_ar" — from Loc_ar.U: the full pathname to ar, whether or not the user specified "portability". Only used in the Makefile.SH. no shortcuts here 👑
"full_csh" — from d_csh.U: the full pathname to csh, whether or not the user specified "portability". Only used in the compiled C program, and the assumption is that all systems which can share this executable will have the same full pathname to csh. the whole friend group shares one address fr fr 🏠
"full_sed" — from Loc_sed.U: the full pathname to sed, whether or not the user specified "portability". Only used in the compiled C program, and again we assume that all systems which can share this executable will have the same full pathname to sed. same deal, different icon 🌟

g 💅

"gccansipedantic" — from gccvers.U: if "GNU" cc (gcc) is being used, setting this variable will enable the -ansi and -pedantic ccflags for building core files (through the cflags script). (See Porting/pumpkin.pod for the full description.) strict mode: activated 🧐
"gccosandvers" — from gccvers.U: if "GNU" cc (gcc) is being used, this holds the operating system and version that was used to compile gcc. It's set to '' if it's not gcc, or if nothing useful can be parsed as the os version. no data, no problem 🙈
"gccversion" — from gccvers.U: if "GNU" cc (gcc) is being used, this holds 1 or 2 to say whether the compiler is version 1 or version 2. Used when setting some of the default cflags. Set to '' if not gcc. shoutout to the OG numbering scheme 🔢
"getgrent_r_proto" — from d_getgrent_r.U: encodes the prototype of getgrent_r. Zero if d_getgrent_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getgrent_r is defined. same pattern, new friend 🦋
"getgrgid_r_proto" — from d_getgrgid_r.U: encodes the prototype of getgrgid_r. Zero if d_getgrgid_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getgrgid_r is defined. 💫
"getgrnam_r_proto" — from d_getgrnam_r.U: encodes the prototype of getgrnam_r. Zero if d_getgrnam_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getgrnam_r is defined. 🎀
"gethostbyaddr_r_proto" — from d_gethostbyaddr_r.U: encodes the prototype of gethostbyaddr_r. Zero if d_gethostbyaddr_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_gethostbyaddr_r is defined. 🌸
"gethostbyname_r_proto" — from d_gethostbyname_r.U: encodes the prototype of gethostbyname_r. Zero if d_gethostbyname_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_gethostbyname_r is defined. ✨
"gethostent_r_proto" — from d_gethostent_r.U: encodes the prototype of gethostent_r. Zero if d_gethostent_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_gethostent_r is defined. 🔥
"getlogin_r_proto" — from d_getlogin_r.U: encodes the prototype of getlogin_r. Zero if d_getlogin_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getlogin_r is defined. 👑
"getnetbyaddr_r_proto" — from d_getnetbyaddr_r.U: encodes the prototype of getnetbyaddr_r. Zero if d_getnetbyaddr_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getnetbyaddr_r is defined. 🌈
"getnetbyname_r_proto" — from d_getnetbyname_r.U: encodes the prototype of getnetbyname_r. Zero if d_getnetbyname_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getnetbyname_r is defined. ⭐
"getnetent_r_proto" — from d_getnetent_r.U: encodes the prototype of getnetent_r. Zero if d_getnetent_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getnetent_r is defined. 💜
"getprotobyname_r_proto" — from d_getprotobyname_r.U: encodes the prototype of getprotobyname_r. Zero if d_getprotobyname_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getprotobyname_r is defined. 🧚
"getprotobynumber_r_proto" — from d_getprotobynumber_r.U: encodes the prototype of getprotobynumber_r. Zero if d_getprotobynumber_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getprotobynumber_r is defined. 🍓
"getprotoent_r_proto" — from d_getprotoent_r.U: encodes the prototype of getprotoent_r. Zero if d_getprotoent_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getprotoent_r is defined. 💖
"getpwent_r_proto" — from d_getpwent_r.U: encodes the prototype of getpwent_r. Zero if d_getpwent_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getpwent_r is defined. 🎀
"getpwnam_r_proto" — from d_getpwnam_r.U: encodes the prototype of getpwnam_r. Zero if d_getpwnam_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getpwnam_r is defined. 🦋
"getpwuid_r_proto" — from d_getpwuid_r.U: encodes the prototype of getpwuid_r. Zero if d_getpwuid_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getpwuid_r is defined. ✨
"getservbyname_r_proto" — from d_getservbyname_r.U: encodes the prototype of getservbyname_r. Zero if d_getservbyname_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getservbyname_r is defined. 🌸
"getservbyport_r_proto" — from d_getservbyport_r.U: encodes the prototype of getservbyport_r. Zero if d_getservbyport_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getservbyport_r is defined. 💅
"getservent_r_proto" — from d_getservent_r.U: encodes the prototype of getservent_r. Zero if d_getservent_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getservent_r is defined. 🌟
"getspnam_r_proto" — from d_getspnam_r.U: encodes the prototype of getspnam_r. Zero if d_getspnam_r is undef, one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_getspnam_r is defined. and that's the last of the _r_proto girlies for now, we survived 😭🫶
"gidformat" — from gidf.U: contains the format string used for printing a Gid_t. printf but make it group-y 🖨️
"gidsign" — from gidsign.U: contains the signedness of a gidtype. 1 for unsigned, -1 for signed. two moods only ⚖️
"gidsize" — from gidsize.U: contains the size of a gidtype in bytes. 📏
"gidtype" — from gidtype.U: defines Gid_t to be something like gid_t, int, ushort, or whatever type is used to declare the return type of getgid(). Typically it's the type of group ids in the kernel. main character type definition 👑
"glibpth" — from libpth.U: holds the general path (space-separated) used to find libraries. Heads up: it may contain directories that don't even exist on this platform — libpth is the cleaned-up version. so glibpth is the messy draft and libpth is the posted version 💀✨
"gmake" — from Loc.U: …and the page cuts off right there bestie, mid-entry, no description given 🫠 (to be continued in the next part!)
"gmake" — from Loc.U. Lowkey internal-only: Configure uses it to figure out the full pathname (if any) of the gmake program. After Configure runs, the value gets reset to a plain "gmake" and honestly? It's not useful after that. 💅
"gmtime_r_proto" — from d_gmtime_r.U. This one encodes the prototype of gmtime_r. It's zero if d_gmtime_r is undef, and it's one of the "REENTRANT_PROTO_T_ABC" macros from reentr.h if d_gmtime_r is defined. ✨
"gnulibc_version" — from d_gnulibc.U. Holds the version number of the "GNU" C library — usually something like 2.2.5. It's a plain '' if this isn't the "GNU" C library, or if the version is unknown. 🫶
"grep" — from Loc.U. Internal Configure business again: it determines the full pathname (if any) of the grep program, then resets to a plain "grep" and stops being useful. 🎀
"groupcat" — from nis.U. A command that produces the text of the /etc/group file. Normally "cat /etc/group", but it can be "ypcat group" when "NIS" is in play. On some systems, like os390, there may be no equivalent command at all — in which case this variable is unset. 😭
"groupstype" — from groupstype.U. Defines Groups_t as something like gid_t, int, ushort, or whatever type gets used for the second argument to getgroups() and setgroups(). Usually it's the same as gidtype (gid_t), but sometimes it just isn't. 🙈
"gzip" — from Loc.U. Same internal pattern: Configure finds the full pathname (if any) of the gzip program, then resets it to a plain "gzip" and it's not useful after. ⭐

🌸 h 🌸

"h_fcntl" — from h_fcntl.U. This variable gets set in various places to tell i_fcntl that <fcntl.h> should be included. 💖
"h_sysfile" — from h_sysfile.U. Gets set in various places to tell i_sys_file that <sys/file.h> should be included. 🦋
"hint" — from Oldconfig.U. Gives the type of hints used for previous answers. May be one of "default", "recommended" or "previous". iykyk 👑
"hostcat" — from nis.U. A command that produces the text of the /etc/hosts file. Normally "cat /etc/hosts", but can be "ypcat hosts" when "NIS" is used. On some systems, like os390, there may be no equivalent command, in which case this variable is unset. 🌈
"hostgenerate" — from Cross.U. The path to a generate_uudmap binary that can run on the host "OS" when cross-compiling. Useful and available only during Perl build. Empty string '' if not cross-compiling. 🔥
"hostosname" — from Cross.U. The original value of $^O for hostperl when cross-compiling. Super useful for picking the proper tools when running build code in the host. Empty string '' if not cross-compiling. 🧚
"hostperl" — from Cross.U. The path to a miniperl binary that can run on the host "OS" when cross-compiling. Useful and available only during Perl build. Empty string '' if not cross-compiling. 💜
"html1dir" — from html1dir.U. The name of the directory where html source pages are to be put. This one's for pages that describe whole programs, not libraries or modules — it's meant to correspond roughly to section 1 of the Unix manuals. 📚
"html1direxp" — from html1dir.U. Same as the html1dir variable, but filename-expanded at configuration time, so it's convenient to use in makefiles. ✨
"html3dir" — from html3dir.U. The name of the directory where html source pages are to be put. This one's for pages describing libraries or modules, intended to correspond roughly to section 3 of the Unix manuals. 🎀
"html3direxp" — from html3dir.U. Same as the html3dir variable, but filename-expanded at configuration time, for convenient use in makefiles. 💅

💅 i 💅

"i16size" — from perlxv.U. The size of an I16 in bytes. 🍓
"i16type" — from perlxv.U. Contains the C type used for Perl's I16. 🌸
"i32dformat" — from perlx32f.U. Contains the format string used for printing a Perl I32 as a signed decimal integer. 🔥
"i32size" — from perlxv.U. The size of an I32 in bytes. ⭐
"i32type" — from perlxv.U. Contains the C type used for Perl's I32. 💖
"i64size" — from perlxv.U. The size of an I64 in bytes. 🦋
"i64type" — from perlxv.U. Contains the C type used for Perl's I64. 🌈
"i8size" — from perlxv.U. The size of an I8 in bytes. 🧚
"i8type" — from perlxv.U. Contains the C type used for Perl's I8. 👑
"i_arpainet" — from i_arpainet.U. Conditionally defines the "I_ARPA_INET" symbol, indicating whether a C program should include <arpa/inet.h>. 💜
"i_bfd" — from i_bfd.U. Conditionally defines the "I_BFD" symbol, indicating whether a C program can include <bfd.h>. 🫶
"i_bsdioctl" — from i_sysioctl.U. Conditionally defines the "I_SYS_BSDIOCTL" symbol, which tells the C program that <sys/bsdioctl.h> exists and should be included. ✨
"i_crypt" — from i_crypt.U. Conditionally defines the "I_CRYPT" symbol, indicating whether a C program should include <crypt.h>. 💅
"i_db" — from i_db.U. Conditionally defines the "I_DB" symbol, indicating whether a C program may include Berkeley's "DB" include file <db.h>. 🎀
"i_dbm" — from i_dbm.U. Conditionally defines the "I_DBM" symbol, which tells the C program that <dbm.h> exists and should be included. 🔥
"i_dirent" — from i_dirent.U. Conditionally defines "I_DIRENT", which tells the C program it should include <dirent.h>. 🌸
"i_dlfcn" — from i_dlfcn.U. Conditionally defines the "I_DLFCN" symbol, which tells the C program that <dlfcn.h> exists and should be included. ⭐
"i_execinfo" — from i_execinfo.U. Conditionally defines the "I_EXECINFO" symbol, indicating whether a C program may include <execinfo.h>, for backtrace() support. 😭 (emotional support header fr fr)
"i_fcntl" — from i_fcntl.U. Controls the value of "I_FCNTL" (which tells the C program to include <fcntl.h>). 🦋
"i_fenv" — from i_fenv.U. Conditionally defines the "I_FENV" symbol, which tells the C program that <fenv.h> exists and should be included. 🌈
"i_fp" — from i_fp.U. Conditionally defines the "I_FP" symbol, indicating whether a C program should include <fp.h>. 🧚
"i_fp_class" — from i_fp_class.U. Conditionally defines the "I_FP_CLASS" symbol, indicating whether a C program should include <fp_class.h>. 💜
"i_gdbm" — from i_gdbm.U. Conditionally defines the "I_GDBM" symbol, which tells the C program that <gdbm.h> exists and should be included. 👑
"i_gdbm_ndbm" — from i_ndbm.U. Conditionally defines the "I_GDBM_NDBM" symbol, which tells the C program that <gdbm-ndbm.h> exists and should be included. Fun fact: this was the location of the ndbm.h compatibility file in Debian 4.0. 🍓
"i_gdbmndbm" — from i_ndbm.U. Conditionally defines the "I_GDBMNDBM" symbol, which tells the C program that <gdbm/ndbm.h> exists and should be included. And this one was the location of the ndbm.h compatibility file in RedHat 7.1. 💀
"i_grp" — from i_grp.U. Conditionally defines the "I_GRP" symbol, indicating whether a C program should include <grp.h>. 🫶
"i_ieeefp" — from i_ieeefp.U. Conditionally defines the "I_IEEEFP" symbol, indicating whether a C program should include <ieeefp.h>. ✨
"i_inttypes" — from i_inttypes.U. Conditionally defines the "I_INTTYPES" symbol, indicating whether a C program should include <inttypes.h>. 💖
"i_langinfo" — from i_langinfo.U. Conditionally defines the "I_LANGINFO" symbol, indicating whether a C program should include <langinfo.h>. 🌸
"i_libutil" — from i_libutil.U. Conditionally defines the "I_LIBUTIL" symbol, indicating whether a C program should include <libutil.h>. 🎀
"i_locale" — from i_locale.U. Conditionally defines the "I_LOCALE" symbol, indicating whether a C program should include <locale.h>. 🔥
"i_machcthr" — from i_machcthr.U. Conditionally defines the "I_MACH_CTHREADS" symbol, indicating whether a C program should include <mach/cthreads.h>. ⭐
"i_malloc" — from i_malloc.U. Conditionally defines the "I_MALLOC" symbol, indicating whether a C program should include <malloc.h>. 🦋
"i_mallocmalloc" — from i_mallocmalloc.U. Conditionally defines the "I_MALLOCMALLOC" symbol, indicating whether a C program should include <malloc/malloc.h>. 🌈
"i_mntent" — from i_mntent.U. Conditionally defines the "I_MNTENT" symbol, indicating whether a C program should include <mntent.h>. 🧚
"i_ndbm" — from i_ndbm.U. Conditionally defines the "I_NDBM" symbol, which tells the C program that <ndbm.h> exists and should be included. 💜
"i_netdb" — from i_netdb.U. Conditionally defines the "I_NETDB" symbol, indicating whether a C program should include <netdb.h>. 👑
"i_neterrno" — from i_neterrno.U. Conditionally defines the "I_NET_ERRNO" symbol, which tells the C program that <net/errno.h> exists and should be included. 🍓
"i_netinettcp" — from i_netinettcp.U. Conditionally defines the "I_NETINET_TCP" symbol, indicating whether a C program should include <netinet/tcp.h>. 😭
i_niin — from i_niin.U: this one conditionally defines I_NETINET_IN, which is the signal to your C program that it should include <netinet/in.h>. Otherwise? You may try <sys/in.h>. That's the fallback, bestie 💅
i_poll — from i_poll.U: conditionally defines the I_POLL symbol, and tells you whether a C program should include <poll.h>.
i_prot — from i_prot.U: conditionally defines the I_PROT symbol, and says whether a C program should include <prot.h>.
i_pthread — from i_pthread.U: conditionally defines the I_PTHREAD symbol, and says whether a C program should include <pthread.h>. threads era ✨
i_pwd — from i_pwd.U: conditionally defines I_PWD, which tells the C program it should include <pwd.h>.
i_quadmath — from i_quadmath.U: conditionally defines I_QUADMATH, which tells the C program it should include <quadmath.h>.
i_rpcsvcdbm — from i_dbm.U: conditionally defines the I_RPCSVC_DBM symbol, which means <rpcsvc/dbm.h> exists and should be included. Heads up: some System V systems might need this instead of <dbm.h>. iykyk 🌸
i_sgtty — from i_termio.U: conditionally defines the I_SGTTY symbol, which tells the C program to include <sgtty.h> rather than <termio.h>.
i_shadow — from i_shadow.U: conditionally defines the I_SHADOW symbol, and says whether a C program should include <shadow.h>.
i_socks — from i_socks.U: conditionally defines the I_SOCKS symbol, and says whether a C program should include <socks.h>.
i_stdbool — from i_stdbool.U: conditionally defines the I_STDBOOL symbol, which tells the C program that <stdbool.h> exists and should be included. true/false girlies rise 🫶
i_stdint — from i_stdint.U: conditionally defines the I_STDINT symbol, which tells the C program that <stdint.h> exists and should be included.
i_stdlib — from i_stdlib.U: this one unconditionally defines the I_STDLIB symbol. no vibe check needed, it just does it 💅
i_sunmath — from i_sunmath.U: conditionally defines the I_SUNMATH symbol, and says whether a C program should include <sunmath.h>.
i_sysaccess — from i_sysaccess.U: conditionally defines the I_SYS_ACCESS symbol, and says whether a C program should include <sys/access.h>.
i_sysdir — from i_sysdir.U: conditionally defines the I_SYS_DIR symbol, and says whether a C program should include <sys/dir.h>.
i_sysfile — from i_sysfile.U: conditionally defines the I_SYS_FILE symbol, and says whether a C program should include <sys/file.h> to get R_OK and friends. iconic little crew 🎀
i_sysfilio — from i_sysioctl.U: conditionally defines the I_SYS_FILIO symbol, which tells the C program that <sys/filio.h> exists and should be included in preference to <sys/ioctl.h>. priority queen 👑
i_sysin — from i_niin.U: conditionally defines I_SYS_IN, which tells the C program it should include <sys/in.h> instead of <netinet/in.h>.
i_sysioctl — from i_sysioctl.U: conditionally defines the I_SYS_IOCTL symbol, which tells the C program that <sys/ioctl.h> exists and should be included.
i_syslog — from i_syslog.U: conditionally defines the I_SYSLOG symbol, and says whether a C program should include <syslog.h>.
i_sysmman — from i_sysmman.U: conditionally defines the I_SYS_MMAN symbol, and says whether a C program should include <sys/mman.h>.
i_sysmode — from i_sysmode.U: conditionally defines the I_SYSMODE symbol, and says whether a C program should include <sys/mode.h>.
i_sysmount — from i_sysmount.U: conditionally defines the I_SYSMOUNT symbol, and says whether a C program should include <sys/mount.h>.
i_sysndir — from i_sysndir.U: conditionally defines the I_SYS_NDIR symbol, and says whether a C program should include <sys/ndir.h>.
i_sysparam — from i_sysparam.U: conditionally defines the I_SYS_PARAM symbol, and says whether a C program should include <sys/param.h>.
i_syspoll — from i_syspoll.U: conditionally defines the I_SYS_POLL symbol, which tells the C program it should include <sys/poll.h>.
i_sysresrc — from i_sysresrc.U: conditionally defines the I_SYS_RESOURCE symbol, and says whether a C program should include <sys/resource.h>.
i_syssecrt — from i_syssecrt.U: conditionally defines the I_SYS_SECURITY symbol, and says whether a C program should include <sys/security.h>.
i_sysselct — from i_sysselct.U: conditionally defines I_SYS_SELECT, which tells the C program it should include <sys/select.h> in order to get the definition of struct timeval.
i_syssockio — from i_sysioctl.U: conditionally defines I_SYS_SOCKIO to tell the C program that socket ioctl codes may be found in <sys/sockio.h> instead of <sys/ioctl.h>.
i_sysstat — from i_sysstat.U: conditionally defines the I_SYS_STAT symbol, and says whether a C program should include <sys/stat.h>.
i_sysstatfs — from i_sysstatfs.U: conditionally defines the I_SYSSTATFS symbol, and says whether a C program should include <sys/statfs.h>.
i_sysstatvfs — from i_sysstatvfs.U: conditionally defines the I_SYSSTATVFS symbol, and says whether a C program should include <sys/statvfs.h>.
i_syssyscall — from i_syssyscall.U: conditionally defines the I_SYS_SYSCALL symbol, and says whether a C program should include <sys/syscall.h>.
i_systime — from i_time.U: conditionally defines I_SYS_TIME, which tells the C program it should include <sys/time.h>.
i_systimek — from i_time.U: conditionally defines I_SYS_TIME_KERNEL, which tells the C program it should include <sys/time.h> with KERNEL defined. kernel-mode arc 😭
i_systimes — from i_systimes.U: conditionally defines the I_SYS_TIMES symbol, and says whether a C program should include <sys/times.h>.
i_systypes — from i_systypes.U: conditionally defines the I_SYS_TYPES symbol, and says whether a C program should include <sys/types.h>.
i_sysuio — from i_sysuio.U: conditionally defines the I_SYSUIO symbol, and says whether a C program should include <sys/uio.h>.
i_sysun — from i_sysun.U: conditionally defines I_SYS_UN, which tells the C program it should include <sys/un.h> to get UNIX domain socket definitions.
i_sysutsname — from i_sysutsname.U: conditionally defines the I_SYSUTSNAME symbol, and says whether a C program should include <sys/utsname.h>.
i_sysvfs — from i_sysvfs.U: conditionally defines the I_SYSVFS symbol, and says whether a C program should include <sys/vfs.h>.
i_syswait — from i_syswait.U: conditionally defines I_SYS_WAIT, which tells the C program it should include <sys/wait.h>.
i_termio — from i_termio.U: conditionally defines the I_TERMIO symbol, which tells the C program to include <termio.h> rather than <sgtty.h>.
i_termios — from i_termio.U: conditionally defines the I_TERMIOS symbol, which tells the C program that the POSIX <termios.h> file is the one to be included. posix bestie stays winning 💅
i_time — from i_time.U: this one unconditionally defines I_TIME, which tells the C program it should include <time.h>.
i_unistd — from i_unistd.U: conditionally defines the I_UNISTD symbol, and says whether a C program should include <unistd.h>.
i_ustat — from i_ustat.U: conditionally defines the I_USTAT symbol, and says whether a C program should include <ustat.h>.
i_utime — from i_utime.U: conditionally defines the I_UTIME symbol, and says whether a C program should include <utime.h>.
i_vfork — from i_vfork.U: conditionally defines the I_VFORK symbol, and says whether a C program should include vfork.h. (yep, no angle brackets on that one — that's literally how it's written, don't come for me 🫶)
i_wchar — from i_wchar.U: conditionally defines the I_WCHAR symbol, that says whether a C program may include <wchar.h>.
i_wctype — from i_wctype.U: conditionally defines the I_WCTYPE symbol, that says whether a C program may include <wctype.h>.
i_xlocale — from d_newlocale.U: this symbol, if defined, tells the C program that the header xlocale.h is available. See also xlocale_needed 👀
ignore_versioned_solibs — from libs.U: this variable should be non-empty if non-versioned shared libraries (libfoo.so.x.y) are to be ignored — because they cannot be linked against. so like, set it and those bad boys get skipped 💀
inc_version_list — from inc_version_list.U: this variable specifies the list of subdirectories over which perl.c:incpush() and lib/lib.pm will automatically search when adding directories to @INC. The elements in the list are separated by spaces. This is only useful if you have a perl library directory tree structured like the default one. See INSTALL for how this works. Fun fact ✨ the versioned site_perl directory was introduced in 5.005, so that is the lowest possible value. periodt.

That list right there is doing the absolute most: it's every architecture-dependent directory back to version $api_versionstring (like, 5.5.640 vibes) plus every architecture-independent directory all the way back to 5.005. History lesson but make it directory paths 💅

🫶 `inc_version_list_init`

From inc_version_list.U:

Okay so this one is literally inc_version_list's twin — same list, but every item is wrapped in double quotes and separated by commas, so it's ready to drop straight into the PERL_INC_VERSION_LIST initialization. Iconic formatting queen ✨

🌸 `incpath`

From usrinc.U:

This variable has to come before the normal include path or you won't get the right one, bestie — like $incpath/usr/include or $incpath/usr/lib. Value can be "" or /bsd43 on mips. Yeah. That's the whole range 😭

🦋 `incpth`

From libpth.U:

Same energy as incpath, different source file — this variable must precede the normal include path to get the right one, as in $incpath/usr/include or $incpath/usr/lib. Value can be "" or /bsd43 on mips. (Yes it reuses $incpath in the example. That's exactly what the page says. Not my business 💀)

💀 `inews`

From Loc.U:

Not me telling you this variable is defined but not used by Configure at all. The value is the empty string and it is not useful. That's it. That's the entry. A whole variable for nothing 🙈

🎀 `initialinstalllocation`

From bin.U:

When userelocatableinc is true, this one holds the location that make install should copy the perl binary to, with all the run-time relocatable paths calculated from this at install time. When it's used, it gets initialized to the original value of binexp, and then binexp is set to .../, because the other binaries are found relative to the perl binary. Sneaky but genius 🧚

💖 `installarchlib`

From archlib.U:

Honestly? It's the same as archlibexp, except on systems using AFS where they may differ. For extra portability, only this variable should be used in makefiles. Periodt ✨

🌈 `installbin`

From bin.U:

Same as binexp — unless AFS is running, in which case the user gets explicitly prompted for it. Always use this one in your makefiles for maximum portability, no cap 🫶

🍓 `installhtml1dir`

From html1dir.U:

Really the same as html1direxp, unless you're using a different installprefix. For extra portability, only use this one inside your makefiles 💅

🧚 `installhtml3dir`

From html3dir.U:

Same deal as its sibling: really the same as html3direxp, unless you're using a different installprefix. For extra portability, only use this variable within your makefiles ✨

👑 `installman1dir`

From man1dir.U:

Really the same as man1direxp, unless you're using AFS — in which case it points at the read/write location, whereas man1direxp only points at the read-only access location. For extra portability, only use this variable within your makefiles, bestie 🎀

🌸 `installman3dir`

From man3dir.U:

Mirror mirror: really the same as man3direxp, unless you're using AFS, where it points to the read/write location while man3direxp only points to the read-only access location. For extra portability, only use this one within your makefiles 💜

🦋 `installprefix`

From installprefix.U:

This holds the name of the directory below which make install will install the package. For most people it's the same as prefix — but the glow-up is that it's useful for installing the software into a different (usually temporary) location, after which you can bundle it up and move it somehow to the final location specified by prefix. Stage it, ship it, slay 💅

⭐ `installprefixexp`

From installprefix.U:

Holds the full absolute path of installprefix, with all the ~-expansion done. Glow-up complete ✨

💖 `installprivlib`

From privlib.U:

Really the same as privlibexp, but may differ on systems using AFS. For extra portability, only this variable should be used in makefiles 🫶

🎀 `installscript`

From scriptdir.U:

Usually the same as scriptdirexp, unless you're on a system running AFS, in which case they may differ slightly. Always use this variable within your makefiles for portability, okay? Okay 💜

🌈 `installsitearch`

From sitearch.U:

Really the same as sitearchexp but may differ on systems using AFS. For extra portability, only this variable should be used in makefiles ✨

🍓 `installsitebin`

From sitebin.U:

Usually the same as sitebinexp, unless you're on a system running AFS, where they may differ slightly. Always use this variable within your makefiles for portability 🧚

👑 `installsitehtml1dir`

From sitehtml1dir.U:

Really the same as sitehtml1direxp, unless you're using AFS, in which case it points to the read/write location whereas html1direxp only points to the read-only access location. For extra portability, only use this variable within your makefiles 💅

🌸 `installsitehtml3dir`

From sitehtml3dir.U:

Really the same as sitehtml3direxp, unless you're using AFS — then it's the read/write location, and html3direxp is only the read-only access location. For extra portability, only use this variable within your makefiles 🎀

💜 `installsitelib`

From sitelib.U:

Really the same as sitelibexp but may differ on systems using AFS. For extra portability, only this variable should be used in makefiles ✨

🦋 `installsiteman1dir`

From siteman1dir.U:

Really the same as siteman1direxp, unless you're using AFS, in which case it points to the read/write location whereas man1direxp only points to the read-only access location. For extra portability, only use this variable within your makefiles 💖

⭐ `installsiteman3dir`

From siteman3dir.U:

Really the same as siteman3direxp, unless you're using AFS, where it points to the read/write location while man3direxp only points to the read-only access location. For extra portability, only use this variable within your makefiles 🌈

🍓 `installsitescript`

From sitescript.U:

Usually the same as sitescriptexp, unless you're on a system running AFS, in which case they may differ slightly. Always use this variable within your makefiles for portability 🫶

👑 `installstyle`

From installstyle.U:

Okay this one's a whole personality trait — it describes the "style" of the perl installation, and it's intended to be useful for tools that need to manipulate entire perl distributions. Important: perl itself doesn't use this to find its libraries — the library directories are stored directly in Config.pm. Currently there are only two styles: lib and lib/perl5. The default library locations (e.g. privlib, sitelib) are either $prefix/lib or $prefix/lib/perl5. The former is useful if $prefix is a directory dedicated to perl (e.g. /opt/perl), while the latter is useful if $prefix is shared by many packages, e.g. if $prefix=/usr/local.

Unfortunately — and yes this is the messy part 😭 — while this "style" variable is used to set defaults for all three directory hierarchies (core, vendor, and site), there's no guarantee that the same style is actually appropriate for all of those directories. For example, $prefix might be /opt/perl, but $siteprefix might be /usr/local. (Perhaps, in retrospect, the lib style should never have been supported, but it did seem like a nice idea at the time. We've all been there 💀)

The situation is even less clear for tools such as MakeMaker that can be used to install additional modules into non-standard places. For example, if a user intends to install a module into a private directory (perhaps by setting PREFIX on the Makefile.PL command line), then there's no reason to assume that the Configure-time $installstyle setting will be relevant for that PREFIX.

Heads up bestie: this may later be extended to include other information, so be careful with pattern-matching on the results 🔥

For compatibility with perl5.005 and earlier, the default setting is based on whether or not $prefix contains the string perl. Vintage behaviour, we respect it ✨

🧚 `installusrbinperl`

From instubperl.U:

Tells you whether Perl should be installed also as /usr/bin/perl in addition to $installbin/perl. Two perls, twice the slay 💅

💜 `installvendorarch`

From vendorarch.U:

Really the same as vendorarchexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles 🫶

🎀 `installvendorbin`

From vendorbin.U:

Really the same as vendorbinexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles ✨

🌸 `installvendorhtml1dir`

From vendorhtml1dir.U:

Really the same as vendorhtml1direxp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles 🦋

⭐ `installvendorhtml3dir`

From vendorhtml3dir.U:

Really the same as vendorhtml3direxp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles 🌈

💖 `installvendorlib`

From vendorlib.U:

Really the same as vendorlibexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles 🍓

👑 `installvendorman1dir`

From vendorman1dir.U:

Really the same as vendorman1direxp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles 🧚

🦋 `installvendorman3dir`

From vendorman3dir.U:

Really the same as vendorman3direxp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles 💜

🌈 `installvendorscript`

From vendorscript.U:

Really the same as vendorscriptexp but may differ on those systems using AFS. For extra portability, only this variable should be used in makefiles 🎀

🍓 `intsize`

From intsize.U:

Contains the value of the INTSIZE symbol, which tells the C program how many bytes there are in an int. Finally, an easy one 😭✨

⭐ `issymlink`

From issymlink.U:

Holds the test command used to check for a symbolic link (if they're supported). Typical values include test -h and test -L. Short, sweet, and doing exactly what it says on the tin 💅

k 🎀

known_extensions — from Extensions.U: okay so this one holds a whole list of, like, every extension (both XS and non-xs 💅) that made it into the package source distribution. Real talk though? It's only genuinely useful during the Perl build, because the list does not tell apart the extensions that got built and installed from the ones that didn't. For the list of extensions that actually got built and are available, go look at extensions instead. ✨
ksh — from Loc.U: defined but literally not used by Configure at all. The value is the empty string and it is not useful. That's it, that's the whole vibe. 💀

l 🦋

ld — from dlsrc.U: tells you which program gets used to link libraries for dynamic loading. On some systems it's ld; on ELF systems it should be $cc. Mostly we'll try to respect whatever the hint file set. 🫶
ld_can_script — from dlsrc.U: shows whether the loader accepts scripts in the form of -Wl,--version-script=ld.script. Currently this is only supported for GNU ld on ELF in dynamic loading builds. No cap. ✨
lddlflags — from dlsrc.U: contains any special flags that might need to get passed to $ld to create a shared library suitable for dynamic loading. It's up to the makefile to actually use it, bestie. For hpux it should be -b; for sunos 4.1 it's empty. 🎀
ldflags — from ccflags.U: holds any additional C loader flags the user wants. Up to the Makefile to use this one. 💅
ldflags_uselargefiles — from uselfs.U: the loader flags needed by large file builds, added to ldflags by hints files. 💖
ldlibpthname — from libperl.U: holds the name of the shared library search path — often LD_LIBRARY_PATH, iykyk. If you want an empty string out of it, the hints file has to set this to none. 🌸
less — from Loc.U: used internally by Configure to figure out the full pathname (if any) of the less program. After Configure runs, the value gets reset to a plain less and is not useful. 🙈
lib_ext — from Unix.U: this is an old synonym for _a. Vintage. 👑
libc — from libc.U: contains the location of the C library. ⭐
libperl — from libperl.U: so the perl executable gets obtained by linking perlmain.c with libperl, any static extensions (usually just DynaLoader), and any other libraries needed on this system. libperl is usually libperl.a, but it can also be libperl.so.xxx if the user wants to build a perl executable with a shared library. Slay. 🔥
libpth — from libpth.U: holds the general path (space-separated) used to find libraries. It's intended to be used by other units. 🧚
libs — from libs.U: holds the additional libraries we want to use. Up to the Makefile to deal with it — and the list can be empty, nbd. 💜
libsdirs — from libs.U: holds the directory names aka dirnames of the libraries we found and accepted; duplicates are removed. ✨
libsfiles — from libs.U: holds the filenames aka basenames of the libraries we found and accepted. 🎀
libsfound — from libs.U: holds the full pathnames of the libraries we found and accepted. 🫶
libspath — from libs.U: holds the directory names probed for libraries. 🌈
libswanted — from Myinit.U: holds a list of all the libraries we want to search. The order is chosen to pick up the c library ahead of ucb or bsd libraries for SVR4. Main character ordering energy. 👑
libswanted_uselargefiles — from uselfs.U: contains the libraries needed by large file builds, added to ldflags by hints files. It's a space-separated list of library names without the lib prefix or any suffix, just like libswanted. 💅
line — from Loc.U: defined but not used by Configure. Value is the empty string, not useful. 💀
lint — from Loc.U: same story, bestie — defined but not used by Configure, value is the empty string, not useful. 💀
lkflags — from ccflags.U: holds any additional C partial linker flags the user wants. Up to the Makefile to use this. 🦋
ln — from Loc.U: used internally by Configure to determine the full pathname (if any) of the ln program. After Configure runs the value is reset to a plain ln and is not useful. 🙈
lns — from lns.U: holds the name of the command that makes symbolic links (if they're supported). It can be used in the Makefile. It's either ln -s or ln. 🌸
localtime_r_proto — from d_localtime_r.U: encodes the prototype of localtime_r. It's zero if d_localtime_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_localtime_r is defined. ⭐
locincpth — from ccflags.U: contains a list of additional directories for the compiler to search. The appropriate -I directives get added to ccflags. This is meant to simplify setting local directories from the Configure command line. It's not much, but it parallels the loclibpth stuff in libpth.U. 🎀
loclibpth — from libpth.U: holds the paths (space-separated) used to find local libraries. It gets prepended to libpth, and it's intended to be easily set from the command line. 💜
longdblinfbytes — from infnan.U: contains a comma-separated list of hexadecimal bytes for the long double precision infinity. 🔥
longdblkind — from d_longdbl.U: if defined, this one encodes the type of a long double, and the vibes are very specific:
- 0 = double
- 1 = IEEE 754 128-bit little endian
- 2 = IEEE 754 128-bit big endian
- 3 = x86 80-bit little endian
- 4 = x86 80-bit big endian
- 5 = double-double 128-bit little endian
- 6 = double-double 128-bit big endian
- 7 = 128-bit mixed-endian double-double (64-bit LEs in BE)
- 8 = 128-bit mixed-endian double-double (64-bit BEs in LE)
- 9 = 128-bit PDP-style mixed-endian long doubles
- -1 = unknown format 💀
longdblmantbits — from mantbits.U: this symbol, if defined, tells how many mantissa bits there are in long double precision floating point format. Note that this can be LDBL_MANT_DIG minus one, since LDBL_MANT_DIG can include the IEEE 754 implicit bit. The common x86-style 80-bit long double does not have an implicit bit. 🧚
longdblnanbytes — from infnan.U: contains a comma-separated list of hexadecimal bytes for the long double precision not-a-number. 🙈
longdblsize — from d_longdbl.U: contains the value of the LONG_DOUBLESIZE symbol, which tells the C program how many bytes there are in a long double, if this system supports long doubles. Note that this is sizeof(long double), which may include unused bytes. 💅
longlongsize — from d_longlong.U: contains the value of the LONGLONGSIZE symbol, which tells the C program how many bytes there are in a long long, if this system supports long long. 🌈
longsize — from intsize.U: contains the value of the LONGSIZE symbol, which tells the C program how many bytes there are in a long. 🦋
lp — from Loc.U: defined but not used by Configure. Empty string, not useful. 💀
lpr — from Loc.U: defined but not used by Configure. Empty string, not useful. 💀
ls — from Loc.U: used internally by Configure to determine the full pathname (if any) of the ls program. After Configure runs, the value is reset to a plain ls and is not useful. ✨
lseeksize — from lseektype.U: defines lseektype to be something like off_t, long, or whatever type is used to declare lseek offset's type in the kernel (which also appears to be lseek's return type). 🎀
lseektype — from lseektype.U: same deal — defines lseektype to be something like off_t, long, or whatever type is used to declare lseek offset's type in the kernel (which also appears to be lseek's return type). Twin energy. 💜

m 🍓

mail — from Loc.U: defined but not used by Configure. Empty string, not useful. 💀
mailx — from Loc.U: defined but not used by Configure. Empty string, not useful. 💀
make — from Loc.U: used internally by Configure to determine the full pathname (if any) of the make program. After Configure runs, the value is reset to a plain make and is not useful. 🙈
make_set_make — from make.U: okay so some versions of make set the variable MAKE, and others simply do not. This variable contains the string to be included in Makefile.SH so that MAKE is set if needed, and not set if not needed. Possible values are:

make_set_make="#"        # If your make program handles this for you,

make_set_make="MAKE=$make"    # if it doesn't.

This uses a comment character so that we can distinguish a "set" value (from a previous config.sh or a Configure -D option) from an uncomputed value. Big brain moves only. 🧠✨

mallocobj — from mallocsrc.U: contains the name of the malloc.o that this package generates, if that malloc.o is preferred over the system malloc. Otherwise the value is null. Intended for generating Makefiles. See mallocsrc. 🫶
mallocsrc — from mallocsrc.U: contains the name of the malloc.c that comes with the package, if that malloc.c is preferred over the system malloc. Otherwise the value is null. Intended for generating Makefiles. 💖

malloctype — from mallocsrc.U

This one holds the actual kind of pointer that malloc and realloc hand back to you. 💅 Like, what type even is that ptr, bestie.

man1dir — from man1dir.U

Holds the name of the directory where manual source pages get put. But plot twist: it's Makefile.SH's job to get this value into the right command. And you have to be ready to do the ~name expansion yourself — no cap, nobody's doing it for you. 😭

man1direxp — from man1dir.U

Literally the same as man1dir but filename-expanded at configuration time, so it's convenient to use up in your makefiles. 🎀

man1ext — from man1dir.U

This is the extension your manual page should have: one of "n", "l", or 1. The Makefile must supply the .. — see man1dir for the whole vibe. ✨

man3dir — from man3dir.U

The directory name where manual source pages go (the section-3 edition 🫶). Again, Makefile.SH is responsible for getting this into the proper command, and yes, you're on ~name expansion duty yourself.

man3direxp — from man3dir.U

Same as man3dir, but filename-expanded at configuration time for convenient makefile use. Iconic behaviour, honestly. 💖

man3ext — from man3dir.U

The extension the manual page should have: one of "n", "l", or 3. Makefile supplies the ... See man3dir.

mips_type — from usrinc.U

Holds the environment type for the mips system. Possible values: "BSD 4.3" and "System V". That's the whole list, she's simple like that. 🦋

mistrustnm — from Csym.U

Okay so this one sets up a fallthrough for when nm just fails to find a symbol. 😤 The rules are very specific, so listen up:

If usenm is false — OR usenm is true and mistrustnm is false — this variable does nothing. Zero effect.
If usenm is true and mistrustnm is "compile", a test program gets compiled to try to find any symbol that can't be located via nm lookup.
If mistrustnm is "run", that test program gets run as well as being compiled.

mkdir — from Loc.U

Used internally by Configure to determine the full pathname (if any) of the mkdir program. After Configure runs, the value is reset to a plain "mkdir" and is not useful. 💀 Internal only, don't @ her.

mmaptype — from d_mmap.U

Contains the type of pointer returned by mmap() — and simultaneously the type of the first argument, because they match. Can be "void *" or "caddr_t". Two jobs, one variable, main character energy. 👑

modetype — from modetype.U

Defines modetype to be something like mode_t, int, unsigned short, or whatever type your system uses to declare file modes for system calls. It's giving "we'll figure it out when we get there". 🌸

more — from Loc.U

Internal Configure business: finds the full pathname (if any) of the more program. After Configure runs it's reset to a plain "more" and is not useful. 🙈

multiarch — from multiarch.U

Conditionally defines the "MULTIARCH" symbol, which signifies the presence of multiplatform files. Normally set by hints files — so like, not your problem, the hints file handles it. 💅

mv — from Loc.U

Defined but not used by Configure. The value is the empty string and is not useful. She's here, she's empty, she does nothing. 💀

myarchname — from archname.U

Holds the architecture name computed by Configure in a previous run. Not intended to be perused by any user, and should never be set in a hint file. Hands off, bestie. 🚫

mydomain — from myhostname.U

Contains the eventual value of the "MYDOMAIN" symbol — the domain of the host the program is going to run on. The domain must be appended to myhostname to form a complete host name. And good news: the dot comes with mydomain, so the program doesn't need to supply it. 🎀

myhostname — from myhostname.U

Contains the eventual value of the "MYHOSTNAME" symbol — the name of the host the program is going to run on. The domain is not kept with the hostname; you have to get it from mydomain. And again: the dot comes with mydomain, no need to supply it yourself. 🫶

myuname — from Oldconfig.U

The output of uname -a if that's available — otherwise just the hostname. Then the whole thing is lower-cased and slashes and single quotes get removed. A little glow-up, a little cleanup. ✨

n 🧚

n — from n.U

Contains the "-n" flag if that's what makes the echo command suppress the newline. Otherwise it's null. Correct usage is:

$echo $n "prompt for a question: $c"

That's the whole bit. 😌

need_va_copy — from need_va_copy.U

If this symbol is defined, it means the system stores the variable argument list datatype, va_list, in a format that cannot be copied by simple assignment — so you need some other means when copying is required. And because these systems vary wildly in their provision (or non-provision 😭) of copying mechanisms, handy.h defines a platform-"independent" macro, Perl_va_copy(src, dst), to do the job for you.

Note the scare quotes around "independent" — that's the original, not me being shady. 💀

netdb_hlen_type — from netdbtype.U

Holds the type used for the 2nd argument to gethostbyaddr(). Usually int or size_t or unsigned. Only useful if you have gethostbyaddr(), naturally. 🦋

netdb_host_type — from netdbtype.U

Holds the type used for the 1st argument to gethostbyaddr(). Usually char * or void *, possibly with or without a const prefix. Again: only useful if you have gethostbyaddr(), naturally.

netdb_name_type — from netdbtype.U

Holds the type used for the argument to gethostbyname(). Usually char * or const char *. Only useful if you have gethostbyname(), naturally. 💖

netdb_net_type — from netdbtype.U

Holds the type used for the 1st argument to getnetbyaddr(). Usually int or long. Only useful if you have getnetbyaddr(), naturally. See the pattern? Naturally. 🌸

nm — from Loc.U

Internal Configure use: finds the full pathname (if any) of the nm program. After Configure runs, it's reset to a plain "nm" and is not useful.

nm_opt — from usenm.U

Holds the options that may be necessary for nm. That's it, that's the whole variable.

nm_so_opt — from usenm.U

Holds the options that may be necessary for nm to work on a shared library, but which cannot be used on an archive library. Currently only used by Linux, where nm --dynamic is required to get symbols from an "ELF" library that's been stripped — but nm --dynamic is fatal on an archive library. 😭 Maybe Linux should just always set usenm=false. (That's the manpage's suggestion, not mine, but honestly? Valid.)

nonxs_ext — from Extensions.U

Holds a list of all non-xs extensions built and installed by the package. By default, all distributed non-xs extensions get built — with the exception of platform-specific extensions (currently only one "VMS" specific extension). 👑

nroff — from Loc.U

Internal Configure: determines the full pathname (if any) of the nroff program. After Configure runs, reset to a plain "nroff", not useful.

nvEUformat — from perlxvf.U

Contains the format string used for printing a Perl "NV" using %E-ish floating point format. Uppercase E, bestie, that matters. 🔥

nvFUformat — from perlxvf.U

Contains the format string used for printing a Perl "NV" using %F-ish floating point format. Uppercase F this time.

nvGUformat — from perlxvf.U

Contains the format string used for printing a Perl "NV" using %G-ish floating point format. Uppercase G, you know the drill. 💜

nv_overflows_integers_at — from perlxv.U

Gives the largest integer value that NVs can hold, as a constant floating point expression. If it couldn't be determined, it holds the value 0. So if you see a 0, that means "we don't know", not "zero". 🙈

nv_preserves_uv_bits — from perlxv.U

Indicates how many of bits type uvtype a variable of type nvtype can preserve.

nveformat — from perlxvf.U

Contains the format string used for printing a Perl "NV" using %e-ish floating point format. Lowercase e now. The lowercase squad has arrived. 🎀

nvfformat — from perlxvf.U

Contains the format string used for printing a Perl "NV" using %f-ish floating point format.

nvgformat — from perlxvf.U

Contains the format string used for printing a Perl "NV" using %g-ish floating point format. Yes, there's a whole set. Collect them all. 💅

nvmantbits — from mantbits.U

Tells you how many bits the mantissa of a Perl "NV" has — not including the possible implicit bit. Precise queen. ⭐

nvsize — from perlxv.U

The size of a Perl "NV" in bytes. Heads up though: some floating point formats have unused bytes, so don't assume it's all meaningful. 😭

nvtype — from perlxv.U

Contains the C type used for Perl's "NV". That's the one.

o 🍓

o_nonblock — from nblock_io.U

Bears the symbol value to be used during open() or fcntl() to turn on non-blocking I/O for a file descriptor. If you want to switch between blocking and non-blocking, you may try ioctl("FIOSNBIO") instead — but that's only supported by some devices, so like, no promises. 🤷‍♀️

obj_ext — from Unix.U

This is an old synonym for _o. Retro vibes only.

old_pthread_create_joinable — from d_pthrattrj.U

Defines the constant to use for creating joinable (aka undetached) pthreads. Unused if pthread.h defines "PTHREAD_CREATE_JOINABLE". If it is used, possible values are "PTHREAD_CREATE_UNDETACHED" and "__UNDETACHED". 🧵

optimize — from ccflags.U

Contains any optimizer/debugger flag that should be used. Whether the Makefile actually uses it? Up to the Makefile. Not our circus. 🎪

orderlib — from orderlib.U

This variable is "true" if the components of libraries must be ordered (with lorder $* | tsort) before being placed in an archive. Set it to "false" if ranlib or ar can generate random libraries. Choose wisely. ⚖️

osname — from Oldconfig.U

Contains the operating system name (e.g. sunos, solaris, hpux, etc.). It can be useful later on for setting defaults. Any spaces get replaced with underscores. And if we can't figure it out, it's set to a null string. 😭

osvers — from Oldconfig.U

This variable contains the operating system version (e.g. 4.1.3, 5.2, etc.). It's mainly there to help pick an appropriate hints file, but it can be handy elsewhere for setting defaults too. It's set to '' if we literally cannot figure it out. And like, we try to be flexible about how much of the version number we keep — e.g. if 4.1.1, 4.1.2, and 4.1.3 are basically the same thing for this package, the hints files might just be os_4.0 or os_4.1, etc., and we're not out here keeping a separate file for every little release, bestie 💅

`otherlibdirs`

From otherlibdirs.U:

This variable holds a colon-separated set of paths that the perl binary searches for extra library files or modules 🦋 These directories get tacked onto the end of @"INC". Perl will automatically search below each path for version- and architecture-specific directories — see inc_version_list for more details. A value of " " means "none", and it's used to preserve this value for the next run through Configure.

✨ p ✨

`package`

From package.U:

This variable holds the name of the package being constructed. It's primarily intended for the use of later Configure units 👑

`pager`

From pager.U:

This variable holds the name of the preferred pager on the system. The usual values are (the full pathnames of) more, less, pg, or cat 📄

`passcat`

From nis.U:

This variable holds a command that produces the text of the /etc/passwd file. Normally it's "cat /etc/passwd", but it can be "ypcat passwd" when "NIS" is in use. On some systems, like os390, there may be no equivalent command at all — in that case this variable is unset 😭

`patchlevel`

From patchlevel.U:

The patchlevel level of this package. The value of patchlevel comes from the patchlevel.h file. In a version number like 5.6.1, this is the 6 🔢 In patchlevel.h, it's referred to as "PERL_VERSION".

`path_sep`

From Unix.U:

This is an old synonym for p_ in Head.U — the character used to separate elements in the command shell search "PATH" 🛤️

`perl`

From Loc.U:

This variable is used internally by Configure to figure out the full pathname (if any) of the perl program. After Configure runs, the value is reset to a plain "perl" and is not useful 🙈

`perl5`

From perl5.U:

This variable holds the full path (if any) to a previously installed perl5.005 or later that's suitable for running the script to determine inc_version_list 🔍

`perl_lc_all_category_positions_init`

From disparate_lc_all.U:

This symbol, when defined, gives the C initializer for an array whose element [0] is the first category in the string returned by setlocale("LC_ALL", "NULL") when not all categories are the same, on systems that use a positional notation. After element [0] comes $lc_all_separator_init, then the category given by element [1], and so on. For example, at the time this was written, the value in config.sh for FreeBSD boxes is:

perl_lc_all_category_positions_init='{ 1, 2, 3, 4, 5, 6 }'

And the result of running this program:

"LC_ALL"=C ./perl -Ilib -"MPOSIX" \
                -le 'setlocale("LC_MONETARY", fr_FR.UTF-8); \
                     print setlocale("LC_ALL")'

is:

C/C/fr_FR.UTF-8/C/C/C

This shows that the "LC_MONETARY" category on FreeBSD occupies the third position in the string returned by querying "LC_ALL". (See perl_lc_all_separator for the source of the forward slash 👀)

`perl_lc_all_separator`

From disparate_lc_all.U:

This symbol, when defined, gives the substring — enclosed in double quotes — used to separate categories in the aggregated string returned by setlocale("LC_ALL", "NULL") when not all categories are in the same locale. This is for systems that use a positional notation as opposed to "name=value" pairs 🧩 For example, at the time this was written, the value in config.sh for FreeBSD boxes is:

perl_lc_all_separator="/"

`perl_patchlevel`

From patchlevel.U:

This is the Perl patch level — a numeric change identifier, as defined by whichever source code maintenance system is used to maintain the patches; currently Perforce. It does not correlate with the Perl version numbers or the maintenance-versus-development dichotomy, except by also being increasing 📈

`perl_static_inline`

From d_static_inline.U:

This variable defines the "PERL_STATIC_INLINE" symbol to the best-guess incantation to use for static inline functions. The possibilities include:

static inline       (c99)
static __inline__   (gcc -ansi)
static __inline     ("MSVC")
static _inline      (older "MSVC")
static              (c89 compilers)

`perl_thread_local`

From d_thread_local.U:

This variable gives the value for the "PERL_THREAD_LOCAL" symbol (when defined), which gives a linkage specification for thread-local storage 🧵

`perladmin`

From perladmin.U:

Electronic mail address of the perl5 administrator 📬

`perllibs`

From End.U:

The list of libraries needed by Perl only (any libraries that are only needed by extensions will be dropped, if using dynamic loading) 📚

`perlpath`

From perlpath.U:

This variable holds the eventual value of the "PERLPATH" symbol, which contains the name of the perl interpreter to be used in shell scripts and in the eval "exec" idiom. Heads up though: this variable is not necessarily the pathname of the file containing the perl interpreter — you must append the executable extension (_exe) if it isn't already present ⚠️ And note that Perl code running during the Perl build process cannot reference this variable, because Perl may not have been installed, or even if it has been installed, it may be a different version of Perl. No cap.

`pg`

From Loc.U:

This variable is used internally by Configure to figure out the full pathname (if any) of the pg program. After Configure runs, the value is reset to a plain "pg" and is not useful 🙈

`phostname`

From myhostname.U:

This variable holds the eventual value of the "PHOSTNAME" symbol, which is a command that can be fed to popen() to get the host name. The program should probably not presume that the domain is or isn't there already 🏠

`pidtype`

From pidtype.U:

This variable defines "PIDTYPE" to be something like pid_t, int, ushort, or whatever type is used to declare process ids in the kernel 💠

`plibpth`

From libpth.U:

Holds the private path used by Configure to find out the libraries. Its value is prepended to libpth. This variable takes care of special machines, like the mips. Usually, it should be empty 🫙

`pmake`

From Loc.U:

This variable is defined but not used by Configure. The value is the empty string and is not useful 💀

`pr`

From Loc.U:

This variable is defined but not used by Configure. The value is the empty string and is not useful 💀

`prefix`

From prefix.U:

This variable holds the name of the directory below which the user will install the package. Usually this is /usr/local, and executables go in /usr/local/bin, library stuff in /usr/local/lib, man pages in /usr/local/man, etc. It's only used to set defaults for things in bin.U, mansrc.U, privlib.U, or scriptdir.U 🏗️

`prefixexp`

From prefix.U:

This variable holds the full absolute path of the directory below which the user will install the package. Derived from prefix ✨

`privlib`

From privlib.U:

This variable holds the eventual value of the "PRIVLIB" symbol, which is the name of the private library for this package. It may have a ~ on the front. It's up to the makefile to eventually create this directory while performing installation (with ~ substitution) 🗂️

`privlibexp`

From privlib.U:

This variable is the ~name expanded version of privlib, so that you may use it directly in Makefiles or shell scripts 🐚

`procselfexe`

From d_procselfexe.U:

If d_procselfexe is defined, $procselfexe is the filename of the symbolic link pointing to the absolute pathname of the executing program 🔗

`ptrsize`

From ptrsize.U:

This variable holds the value of the "PTRSIZE" symbol, which tells the C program how many bytes there are in a pointer 📏

🌈 q 🌈

`quadkind`

From quadtype.U:

This variable, if defined, encodes the type of a quad: 1 = int, 2 = long, 3 = long long, 4 = int64_t 🔢

`quadtype`

From quadtype.U:

This variable defines Quad_t to be something like long, int, long long, int64_t, or whatever type is used for 64-bit integers 💪

🎀 r 🎀

`randbits`

From randfunc.U:

Indicates how many bits are produced by the function used to generate normalized random numbers 🎲

`randfunc`

From randfunc.U:

Indicates the name of the random number function to use. Values include drand48, random, and rand. In C programs, the "Drand01" macro is defined to generate uniformly distributed random numbers over the range [0., 1.[ (see drand01 and nrand) 🎰

`random_r_proto`

From d_random_r.U:

This variable encodes the prototype of random_r. It's zero if d_random_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_random_r is defined 🧬

`randseedtype`

From randfunc.U:

Indicates the type of the argument of the seedfunc 🌱

`ranlib`

From orderlib.U:

This variable is set to the pathname of the ranlib program, if it's needed to generate random libraries. Set to ":" if ar can generate random libraries or if random libraries are not supported 🛠️

`rd_nodata`

From nblock_io.U:

This variable holds the return code from read() when no data is present. It should be -1, but some systems return 0 when "O_NDELAY" is used — which is a shame, because you cannot make the difference between no data and an EOF. Sigh! 😤

`readdir64_r_proto`

From d_readdir64_r.U:

This variable encodes the prototype of readdir64_r. It's zero if d_readdir64_r is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if d_readdir64_r is defined 🧬

`readdir_r_proto`

From d_readdir_r.U:

Okay bestie, we're picking up mid-flow here — no heading needed, we're still in the r's 😌

This variable encodes the prototype of readdir_r. It's zero if d_readdir_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_readdir_r is defined. 💅

`revision`

From patchlevel.U:

The value of revision comes from the patchlevel.h file. In a version number like 5.6.1, this is the 5. In patchlevel.h, this is referred to as PERL_REVISION. 🔢

`rm`

From Loc.U:

Configure uses this variable internally to figure out the full pathname (if any) of the rm program. After Configure runs, the value gets reset to a plain rm and is not useful. Bye 👋

`rm_try`

From Unix.U:

This is a cleanup variable for try test programs. Internal Configure use only. 🙈

`rmail`

From Loc.U:

This variable is defined but not used by Configure. The value is the empty string and is not useful. Literally just vibing there doing nothing 🫠

`run`

From Cross.U:

This variable contains the command Configure uses to copy and execute a cross-compiled executable on the target host. Useful and available only during Perl build. It's the empty string '' if you're not cross-compiling. 🏃‍♀️

`runnm`

From usenm.U:

This one holds "true" or "false" depending on whether the nm extraction should be performed or not — decided by the value of usenm and the flags you passed on the Configure command line. ⚖️

✨ s ✨

`sGMTIME_max`

From time_size.U:

This variable defines the maximum value of the time_t offset that the system function gmtime () accepts. ⏰

`sGMTIME_min`

From time_size.U:

This variable defines the minimum value of the time_t offset that the system function gmtime () accepts. ⏰

`sLOCALTIME_max`

From time_size.U:

This variable defines the maximum value of the time_t offset that the system function localtime () accepts. 🌍

`sLOCALTIME_min`

From time_size.U:

This variable defines the minimum value of the time_t offset that the system function localtime () accepts. 🌍

`sPRIEUldbl`

From longdblfio.U:

This variable, if defined, contains the string stdio uses to format long doubles (format "E") for output. The "U" in the name is there to separate it from sPRIeldbl so that even case-blind systems can see the difference. 👀

`sPRIFUldbl`

From longdblfio.U:

This variable, if defined, contains the string stdio uses to format long doubles (format "F") for output. The "U" in the name separates it from sPRIfldbl so that even case-blind systems can see the difference. 👀

`sPRIGUldbl`

From longdblfio.U:

This variable, if defined, contains the string stdio uses to format long doubles (format "G") for output. The "U" in the name separates it from sPRIgldbl so that even case-blind systems can see the difference. 👀

`sPRIXU64`

From quadfio.U:

This variable, if defined, contains the string stdio uses to format 64-bit hExADECimAl numbers (format "X") for output. The "U" in the name separates it from sPRIx64 so that even case-blind systems can see the difference. 💜

`sPRId64`

From quadfio.U:

This variable, if defined, contains the string stdio uses to format 64-bit decimal numbers (format "d") for output.

`sPRIeldbl`

From longdblfio.U:

This variable, if defined, contains the string stdio uses to format long doubles (format "e") for output.

`sPRIfldbl`

From longdblfio.U:

This variable, if defined, contains the string stdio uses to format long doubles (format "f") for output.

`sPRIgldbl`

From longdblfio.U:

This variable, if defined, contains the string stdio uses to format long doubles (format "g") for output.

`sPRIi64`

From quadfio.U:

This variable, if defined, contains the string stdio uses to format 64-bit decimal numbers (format "i") for output.

`sPRIo64`

From quadfio.U:

This variable, if defined, contains the string stdio uses to format 64-bit octal numbers (format "o") for output.

`sPRIu64`

From quadfio.U:

This variable, if defined, contains the string stdio uses to format 64-bit unsigned decimal numbers (format "u") for output.

`sPRIx64`

From quadfio.U:

This variable, if defined, contains the string stdio uses to format 64-bit hexadecimal numbers (format "x") for output.

`sSCNfldbl`

From longdblfio.U:

This variable, if defined, contains the string stdio uses to format long doubles (format "f") for input. 📥

`sched_yield`

From d_pthread_y.U:

This variable defines the way to yield the execution of the current thread. 🤝

`scriptdir`

From scriptdir.U:

This variable holds the name of the directory where the user wants to put publicly scripts for the package in question. It's either the same directory as for binaries, or a special one that can be mounted across different architectures — like /usr/share. Programs must be prepared to deal with ~name expansion. 🗂️

`scriptdirexp`

From scriptdir.U:

This variable is the same as scriptdir, but it's filename-expanded at configuration time, for programs that don't want to bother with it. ✨

`sed`

From Loc.U:

Configure uses this variable internally to figure out the full pathname (if any) of the sed program. After Configure runs, the value is reset to a plain sed and is not useful. 🫶

`seedfunc`

From randfunc.U:

Indicates the random number generating seed function. Values include srand48, srandom, and srand. 🎲

`selectminbits`

From selectminbits.U:

This variable holds the minimum number of bits operated by select. That is, if you do select(n, ...), how many bits at least will be cleared in the masks if some activity is detected. Usually this is either n or 32*ceil(n/32) — especially many little-endians do the latter. This is only useful if you have select(), naturally. 🔍

`selecttype`

From selecttype.U:

This variable holds the type used for the 2nd, 3rd, and 4th arguments to select. Usually, this is "fd_set *", if "HAS_FD_SET" is defined, and "int *" otherwise. This is only useful if you have select(), naturally. 🧐

`sendmail`

From Loc.U:

This variable is defined but not used by Configure. The value is the empty string and is not useful. 📭

`setgrent_r_proto`

From d_setgrent_r.U:

This variable encodes the prototype of setgrent_r. It's zero if d_setgrent_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_setgrent_r is defined.

`sethostent_r_proto`

From d_sethostent_r.U:

This variable encodes the prototype of sethostent_r. It's zero if d_sethostent_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_sethostent_r is defined.

`setlocale_r_proto`

From d_setlocale_r.U:

This variable encodes the prototype of setlocale_r. It's zero if d_setlocale_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_setlocale_r is defined.

`setnetent_r_proto`

From d_setnetent_r.U:

This variable encodes the prototype of setnetent_r. It's zero if d_setnetent_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_setnetent_r is defined.

`setprotoent_r_proto`

From d_setprotoent_r.U:

This variable encodes the prototype of setprotoent_r. It's zero if d_setprotoent_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_setprotoent_r is defined.

`setpwent_r_proto`

From d_setpwent_r.U:

This variable encodes the prototype of setpwent_r. It's zero if d_setpwent_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_setpwent_r is defined.

`setservent_r_proto`

From d_setservent_r.U:

This variable encodes the prototype of setservent_r. It's zero if d_setservent_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_setservent_r is defined.

`sh`

From sh.U:

This variable contains the full pathname of the shell used on this system to execute Bourne shell scripts. Usually this will be /bin/sh, though it's possible that some systems will have /bin/ksh, /bin/pdksh, /bin/ash, /bin/bash, or even something such as D:/bin/sh.exe. 🐚

Heads up bestie: this unit comes before Options.U, so you can't set sh with a -D option — though you can override this (and startsh) with -O -Dsh=/bin/whatever -Dstartsh=whatever 😌

`shar`

From Loc.U:

This variable is defined but not used by Configure. The value is the empty string and is not useful.

`sharpbang`

From spitshell.U:

This variable contains the string #! if this system supports that construct. 🎀

`shmattype`

From d_shmat.U:

This symbol contains the type of pointer returned by shmat(). It can be "void *" or "char *". 👉

`shortsize`

From intsize.U:

This variable contains the value of the "SHORTSIZE" symbol, which tells the C program how many bytes there are in a short. 📏

`shrpenv`

From libperl.U:

If the user builds a shared libperl.so, then we need to tell the "perl" executable where it'll be able to find the installed libperl.so. One way to do this on some systems is to set the environment variable "LD_RUN_PATH" to the directory that will be the final location of the shared libperl.so. The makefile can use this with something like $shrpenv $("CC") -o perl perlmain.o $libperl $libs

Typical values are shrpenv="env "LD_RUN_PATH"=$archlibexp/"CORE"" or shrpenv='' — see the main perl Makefile.SH for actual working usage. 🛠️

Alternatively, we might be able to use a command line option such as -R $archlibexp/"CORE" (Solaris) or -Wl,-rpath $archlibexp/"CORE" (Linux). 🌞

`shsharp`

From spitshell.U:

This variable tells further Configure units whether your sh can handle # comments. 💬

`sig_count`

From sig_name.U:

This variable holds a number larger than the largest valid signal number. This is usually the same as the "NSIG" macro. 🚦

`sig_name`

From sig_name.U:

This variable holds the signal names, space separated. The leading "SIG" in the signal name is removed. A "ZERO" is prepended to the list. This is currently not used — sig_name_init is used instead. 🙃

`sig_name_init`

coming at you from sig_name.U 🎀

This one holds the signal names, all wrapped in double quotes and separated by commas, ready to slot straight into the SIG_NAME definition down below. A ZERO gets prepended to the front of the list, and the list gets closed off with a plain 0. Also the leading SIG in every signal name is stripped off. Cross-ref: see sig_num.

`sig_num`

coming at you from sig_name.U ✨

The signal numbers, space separated. A ZERO is prepended (that's the one corresponding to the fake SIGZERO), and each number lines up with the signal sitting in the same position in the sig_name list. Lowkey iconic alignment. Heads up though: this one is currently not used — sig_num_init is used instead.

`sig_num_init`

coming at you from sig_name.U 💜

The signal numbers again, but this time enclosed in double quotes and separated by commas, suitable for use in the SIG_NUM definition below. A ZERO is prepended to the list, and the list is terminated with a plain 0. Same energy, friendlier packaging.

`sig_size`

coming at you from sig_name.U 🌸

This variable contains the number of elements of the sig_name and sig_num arrays. She's the headcount bestie.

`signal_t`

coming at you from d_voidsig.U 🔥

Holds the type of the signal handler, which is either void or int.

`sitearch`

coming at you from sitearch.U 💖

This variable contains the eventual value of the SITEARCH symbol, which is the name of the private library for this package. It may have a ~ on the front. It is up to the makefile to eventually create this directory while performing installation (with ~ substitution).

The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local architecture-dependent modules in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

`sitearchexp`

coming at you from sitearch.U ⭐

This variable is the ~name expanded version of sitearch, so that you may use it directly in Makefiles or shell scripts. No tilde drama, just vibes.

`sitebin`

coming at you from sitebin.U 🎀

This variable holds the name of the directory in which the user wants to put add-on publicly executable files for the package in question. It is most often a local directory such as /usr/local/bin. Programs using this variable must be prepared to deal with ~name substitution.

The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local executables in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

`sitebinexp`

coming at you from sitebin.U 🦋

Same as the sitebin variable, but filename expanded at configuration time, for use in your makefiles.

`sitehtml1dir`

coming at you from sitehtml1dir.U 🌈

This variable contains the name of the directory in which site-specific html source pages are to be put. Getting the value of this into the proper command is the responsibility of the Makefile.SH — and you must be prepared to do the ~name expansion yourself.

The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local html pages in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

`sitehtml1direxp`

coming at you from sitehtml1dir.U ✨

Same as the sitehtml1dir variable, but filename expanded at configuration time, for convenient use in makefiles.

`sitehtml3dir`

coming at you from sitehtml3dir.U 💅

This variable contains the name of the directory in which site-specific library html source pages are to be put. It is the responsibility of the Makefile.SH to get the value of this into the proper command. You must be prepared to do the ~name expansion yourself.

The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local library html pages in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

`sitehtml3direxp`

coming at you from sitehtml3dir.U 🫶

Same as the sitehtml3dir variable, but filename expanded at configuration time, for convenient use in makefiles.

`sitelib`

coming at you from sitelib.U 💜

This variable contains the eventual value of the SITELIB symbol, which is the name of the private library for this package. It may have a ~ on the front. It is up to the makefile to eventually create this directory while performing installation (with ~ substitution).

The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local architecture-independent modules in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

`sitelib_stem`

coming at you from sitelib.U 🌸

This variable is $sitelibexp with any trailing version-specific component removed. The elements in inc_version_list (inc_version_list.U) can be tacked onto this variable to generate a list of directories to search. She's the stem, the base, the root of the whole glow-up. 🌱

`sitelibexp`

coming at you from sitelib.U ⭐

This variable is the ~name expanded version of sitelib, so that you may use it directly in Makefiles or shell scripts.

`siteman1dir`

coming at you from siteman1dir.U 🎀

This variable contains the name of the directory in which site-specific manual source pages are to be put. It is the responsibility of the Makefile.SH to get the value of this into the proper command. You must be prepared to do the ~name expansion yourself.

The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local man1 pages in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

`siteman1direxp`

coming at you from siteman1dir.U 🦋

Same as the siteman1dir variable, but filename expanded at configuration time, for convenient use in makefiles.

`siteman3dir`

coming at you from siteman3dir.U 🔥

This variable contains the name of the directory in which site-specific library man source pages are to be put. It is the responsibility of the Makefile.SH to get the value of this into the proper command. You must be prepared to do the ~name expansion yourself.

The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local man3 pages in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

`siteman3direxp`

coming at you from siteman3dir.U 🌈

Same as the siteman3dir variable, but filename expanded at configuration time, for convenient use in makefiles.

`siteprefix`

coming at you from siteprefix.U 💖

This variable holds the full absolute path of the directory below which the user will install add-on packages. See INSTALL for usage and examples.

`siteprefixexp`

coming at you from siteprefix.U ✨

This variable holds the full absolute path of the directory below which the user will install add-on packages. It's derived from siteprefix — same truth, already-expanded format.

`sitescript`

coming at you from sitescript.U 🫶

The standard distribution will put nothing in this directory. After perl has been installed, users may install their own local scripts in this directory with MakeMaker Makefile.PL or equivalent. See INSTALL for details.

`sitescriptexp`

coming at you from sitescript.U 💅

Same as the sitescript variable, but filename expanded at configuration time, for use in your makefiles.

`sizesize`

coming at you from sizesize.U 🍓

This variable contains the size of a sizetype in bytes. Yes, the name is a little unhinged. She ate regardless.

`sizetype`

coming at you from sizetype.U 🌸

This variable defines sizetype to be something like size_t, unsigned long, or whatever type is used to declare length parameters for string functions.

`sleep`

coming at you from Loc.U 💀

This variable is defined but not used by Configure. The value is the empty string and is not useful. Literally just here. Decorative. Not me getting main-character billing for doing absolutely nothing. 😭

`smail`

coming at you from Loc.U 💀

This variable is defined but not used by Configure. The value is the empty string and is not useful. Same situation as sleep — present, technically, contributing zero.

`so`

coming at you from so.U 🦋

This variable holds the extension used to identify shared libraries (also known as shared objects) on the system. Usually set to so.

`sockethdr`

coming at you from d_socket.U 🔥

This variable has any cpp -I flags needed for socket support.

`socketlib`

coming at you from d_socket.U 🔥

This variable has the names of any libraries needed for socket support.

`socksizetype`

coming at you from socksizetype.U ⭐

This variable holds the type used for the size argument for various socket calls like accept. Usual values include socklen_t, size_t, and int.

`sort`

coming at you from Loc.U 🎀

This variable is used internally by Configure to determine the full pathname (if any) of the sort program. After Configure runs, the value is reset to a plain sort and is not useful. Glow-up then de-glow-up, tragic honestly.

`spackage`

coming at you from package.U 👑

This variable contains the name of the package being constructed, with the first letter uppercased, i.e. suitable for starting sentences. Capitalized and ready to open a paragraph. Periodt.

`spitshell`

coming at you from spitshell.U 🧚

This variable contains the command necessary to spit out a runnable shell on this system. It is either cat or a grep -v for # comments. Yes, "spit" is the technical term, we don't make the rules. 💅

`srand48_r_proto`

coming at you from d_srand48_r.U 💜

This variable encodes the prototype of srand48_r. It is zero if d_srand48_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_srand48_r is defined.

`srandom_r_proto`

coming at you from d_srandom_r.U 💜

This variable encodes the prototype of srandom_r. It is zero if d_srandom_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_srandom_r is defined.

`src`

coming at you from src.U 🦋

This variable holds the (possibly relative) path of the package source. It is up to the Makefile to use this variable and set VPATH accordingly to find the sources remotely. Use $pkgsrc to have an absolute path instead — that's the one that won't ghost you. 😌

`ssizetype`

coming at you from ssizetype.U 🌈

...and it defines ssizetype to be something like ssize_t, long or int — it's what functions that return a byte count (or an error condition) use. Bestie, it must be a signed type. We'll pick a type such that sizeof(SSize_t) == sizeof(Size_t). ✨

st_dev_sign — from st_dev_def.U: this one holds the signedness of struct stat's st_dev. It's 1 for unsigned, -1 for signed. Simple as.
st_dev_size — from st_dev_def.U: the size of struct stat's st_dev in bytes.
st_ino_sign — from st_ino_def.U: signedness of struct stat's st_ino. Again 1 for unsigned, -1 for signed.
st_ino_size — from st_ino_def.U: the size of struct stat's st_ino in bytes. slay.
startperl — from startperl.U: the string you slap on the front of a perl script so it (hopefully) runs with perl and not some random shell. Of course, that leading line has to be followed by the classic perl idiom:

eval 'exec perl -S $0 ${1+$@}' if
$running_under_some_shell;

...which guarantees perl startup should the shell go ahead and execute the script. Heads up though: this magic incantation is not understood by csh. 💀

startsh — from startsh.U: same vibe, but for shell scripts — the string to put on the front of a shell script so it (hopefully) runs with sh and not some other shell. 🐚
static_ext — from Extensions.U: holds a list of XS extension files we want to link statically into the package. It's used by Makefile.
stdchar — from stdchar.U: conditionally defines STDCHAR to be the type of char used in stdio.h. Its values are "unsigned char" or "char".
stdio_base — from d_stdstdio.U: defines how, given a FILE pointer, fp, to access the _base field (or equivalent) of stdio.h's FILE structure. This gets used to define the macro FILE_base(fp).
stdio_bufsiz — from d_stdstdio.U: defines how, given a FILE pointer, fp, to work out the number of bytes store in the I/O buffer pointer to by the _base field (or equivalent) of stdio.h's FILE structure. Used to define the macro FILE_bufsiz(fp).
stdio_cnt — from d_stdstdio.U: defines how, given a FILE pointer, fp, to access the _cnt field (or equivalent) of stdio.h's FILE structure. Used to define the macro FILE_cnt(fp).
stdio_filbuf — from d_stdstdio.U: defines how, given a FILE pointer, fp, to tell stdio to refill its internal buffers (?). This one gets used to define the macro FILE_filbuf(fp).
stdio_ptr — from d_stdstdio.U: defines how, given a FILE pointer, fp, to access the _ptr field (or equivalent) of stdio.h's FILE structure. Used to define the macro FILE_ptr(fp).
stdio_stream_array — from stdio_streams.U: tells you the name of the array holding the stdio streams. The usual suspects include _iob, __iob, and __sF. 😌
strerror_r_proto — from d_strerror_r.U: encodes the prototype of strerror_r. It's zero if d_strerror_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_strerror_r is defined.
submit — from Loc.U: defined but not used by Configure. The value is the empty string and is not useful. literally just vibing there 💅
subversion — from patchlevel.U: the subversion level of this package. The value comes from the patchlevel.h file. In a version number like 5.6.1, this is the 1. In patchlevel.h, it's referred to as PERL_SUBVERSION. This one's unique to perl, iykyk. 🫶
sysman — from sysman.U: holds the place where the manual is located on this system. It is not the place where the user wants to put his manual pages — rather it's where Configure may look to find the manual for unix commands (section 1 of the manual usually). See mansrc.
sysroot — from Sysroot.U: empty unless supplied by the Configure user. It can contain a path to an alternative root directory, under which headers and libraries for the compilation target can be found. This is generally used when cross-compiling using a gcc-like compiler. cross-compile girlies rise 🦋

✨ t ✨

tail — from Loc.U: defined but not used by Configure. Empty string, not useful. 🙈
taint_disabled — from define: SILENT_NO_TAINT_SUPPORT or NO_TAINT_SUPPORT. If this perl is compiled with support for taint mode, this variable is set to the empty string. If it was compiled with SILENT_NO_TAINT_SUPPORT defined, then it's set to silent. And if it was compiled with NO_TAINT_SUPPORT defined, it'll be 'define'. Either of the above defines results in it being a true value. This property was added in 5.37.11. See also taint_support. 🔥
taint_support — from define: SILENT_NO_TAINT_SUPPORT or NO_TAINT_SUPPORT. If this perl is compiled with support for taint mode, this variable is set to 'define'; if it's not, it's set to the empty string. Either of the above defines will result in it being empty. This property was added in version 5.37.11. See also taint_disabled. ✨
tar — from Loc.U: defined but not used by Configure. Empty string, not useful.
targetarch — from Cross.U: if cross-compiling, contains the target architecture. If not, this will be empty.
targetdir — from Cross.U: a path that will be created on the target host using targetmkdir, and then used to copy the cross-compiled executables to. Defaults to /tmp if not set.
targetenv — from Cross.U: if cross-compiling, this variable can be used to modify the environment on the target system. However — how and where it's used, and even if it's used at all, is entirely dependent on both the transport mechanism (targetrun) and what the target system is. Unless the relevant documentation says otherwise, it's genereally not useful. 😭
targethost — from Cross.U: contains the name of a separate host machine that can be used to run compiled test programs and perl tests on. Set to empty string if not in use.
targetmkdir — from Cross.U: the command used by Configure to create a new directory on the target host.
targetport — from Cross.U: the number of a network port used to connect to the host in targethost; if unset it defaults to 22 for ssh.
targetsh — from sh.U: if cross-compiling, contains the location of sh on the target system. If not, this will be the same as $sh.
tbl — from Loc.U: defined but not used by Configure. Empty string, not useful.
tee — from Loc.U: defined but not used by Configure. Empty string, not useful. bestie it's giving placeholder
test — from Loc.U: used internally by Configure to determine the full pathname (if any) of the test program. After Configure runs, the value is reset to a plain test and is not useful.
timeincl — from i_time.U: holds the full path of the included time header(s).
timetype — from d_time.U: holds the type returned by time(). It can be long, or time_t on BSD sites (in which case <sys/types.h> should be included). Anyway, the type Time_t should be used.
tmpnam_r_proto — from d_tmpnam_r.U: encodes the prototype of tmpnam_r. It's zero if d_tmpnam_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_tmpnam_r is defined.
to — from Cross.U: the command used by Configure to copy to from the target host. Useful and available only during Perl build. The string ":" if not cross-compiling.
touch — from Loc.U: used internally by Configure to determine the full pathname (if any) of the touch program. After Configure runs, the value is reset to a plain touch and is not useful.
tr — from Loc.U: used internally by Configure to determine the full pathname (if any) of the tr program. After Configure runs, the value is reset to a plain tr and is not useful.
trnl — from trnl.U: the value to be passed to the tr(1) command to transliterate a newline. Typical values are "\012" and "\n". This is needed for EBCDIC systems where newline is not necessarily "\012". 👑
troff — from Loc.U: defined but not used by Configure. Empty string, not useful.
ttyname_r_proto — from d_ttyname_r.U: encodes the prototype of ttyname_r. It's zero if d_ttyname_r is undef, and one of the REENTRANT_PROTO_T_ABC macros of reentr.h if d_ttyname_r is defined.

🌈 u 🌈

u16size — from perlxv.U: the size of an U16 in bytes.
u16type — from perlxv.U: the C type used for Perl's U16.
u32XUformat — from perlx32f.U: the format string used for printing a Perl U32 as an unsigned hexadecimal integer in uppercase ABCDEF. 💅
u32oformat — from perlx32f.U: the format string used for printing a Perl U32 as an unsigned octal integer.
u32size — from perlxv.U: the size of an U32 in bytes.
u32type — from perlxv.U: the C type used for Perl's U32.
u32uformat — from perlx32f.U: the format string used for printing a Perl U32 as an unsigned decimal integer.
u32xformat — from perlx32f.U: the format string used for printing a Perl U32 as an unsigned hexadecimal integer in lowercase abcdef. 🎀

"u64size"

From perlxv.U:

this one's literally just the size of an U64 in bytes. that's the whole thing. byte count. slay 💅

"u64type"

From perlxv.U:

holds the actual C type used for Perl's U64. the real type name, in all its glory ✨

"u8size"

From perlxv.U:

the size of an U8 in bytes. tiny little guy, tiny little number 🎀

"u8type"

From perlxv.U:

the C type used for Perl's U8. yes it's a real type name, not a vibe 🌸

"uidformat"

From uidf.U:

this variable holds the format string you use for printing a Uid_t. printf girlies rise 🔥

"uidsign"

From uidsign.U:

the signedness of a uidtype. so it's 1 for unsigned, -1 for signed. that's the whole scale, no in-between, periodt 💜

"uidsize"

From uidsize.U:

size of a uidtype in bytes. number of bytes, nothing more 🦋

"uidtype"

From uidtype.U:

this one defines Uid_t to be something like uid_t, int, ushort, or literally whatever type your kernel uses to declare user ids. iykyk 😌

"uname"

From Loc.U:

bestie this is an internal one 🫶 Configure uses it to figure out the full pathname (if any) of the uname program. but heads up: after Configure runs, the value gets reset to a plain uname and it's not useful anymore. so don't come for it 🙈

"uniq"

From Loc.U:

same energy as uname 💀 internal Configure business — it finds the full pathname (if any) of the uniq program. and again, after Configure runs the value is reset to a plain uniq and it is not useful. moving on ✨

"uquadtype"

From quadtype.U:

defines Uquad_t to be something like unsigned long, unsigned int, unsigned long long, uint64_t, or whatever type gets used for 64-bit integers. pick your fighter 👑

"use64bitall"

From use64bits.U:

conditionally defines the USE_64_BIT_ALL symbol, and it means 64-bit integer types should be used when available. and we're going maximal here — LP64 or ILP64, meaning you'll be able to use more than 2 gigabytes of memory 🔥

⚠️ real talk: this mode is even more binary incompatible than USE_64_BIT_INT. you may not be able to run the resulting executable in a 32-bit "CPU" at all, or you may need at least to reboot your "OS" to 64-bit mode. not exaggerating 💀

"use64bitint"

From use64bits.U:

conditionally defines the USE_64_BIT_INT symbol, indicating 64-bit integer types should be used when available. this one's the minimal 64-bitness — just enough to get 64-bit integers into Perl. it may mean using, for example, "long longs", while your memory may still be limited to 2 gigabytes. lowkey humble about it 🌸

"usecbacktrace"

From usebacktrace.U:

tells you whether we're compiling with backtrace support. yes ma'am, catching those frames 🎀

"usecrosscompile"

From Cross.U:

conditionally defines the USE_CROSS_COMPILE symbol, and says Perl has been cross-compiled. traveling perl, iconic ✈️

"usedefaultstrict"

From usedefaultstrict.U:

this setting is the mechanism for perl developers to enable strict by default. but bestie, heads up: those defaults do not apply when perl is run via -e or -E. so don't get caught out 🙈

"usedevel"

From Devel.U:

indicates that Perl was configured with development features enabled.

🚨 this should not be done for production builds. like, at all. fr fr.

"usedl"

From dlsrc.U:

tells you if the system supports dynamic loading of some sort. see also dlsrc and dlobj 💅

"usedtrace"

From usedtrace.U:

whether we're compiling with dtrace support. see also dtrace. tracing girlies, this is your moment ⭐

"usefaststdio"

From usefaststdio.U:

conditionally defines the USE_FAST_STDIO symbol, meaning Perl should be built to use "fast stdio". the default is to define it in Perls 5.8 and earlier, and to undef it later. era-dependent behavior, we love to see it 🦋

"useithreads"

From usethreads.U:

conditionally defines the USE_ITHREADS symbol, and indicates Perl should be built to use the interpreter-based threading implementation. threads but make it interpreter-based 🧵

"usekernprocpathname"

From usekernprocpathname.U:

this variable indicates that we can use sysctl with KERN_PROC_PATHNAME to get a full path for the executable — and hence convert $^X to an absolute path. no more mystery paths, we love a glow-up ✨

"uselanginfo"

From Extensions.U:

holds either "true" or "false", indicating whether the I18N::Langinfo extension should be used. the sole use for this currently is to give users an easy mechanism to skip this extension from the Configure command line. simple, effective, iconic 🎀

"uselargefiles"

From uselfs.U:

conditionally defines the USE_LARGE_FILES symbol, indicating large file interfaces should be used when available. big files only 💅

"uselongdouble"

From uselongdbl.U:

conditionally defines the USE_LONG_DOUBLE symbol, meaning long doubles should be used when available. extra precision, extra vibes 🔥

"usemallocwrap"

From mallocsrc.U:

contains y if we're wrapping malloc to prevent integer overflow during size calculations. protective king behavior 🛡️

"usemorebits"

From usemorebits.U:

conditionally defines the USE_MORE_BITS symbol, and says explicit 64-bit interfaces and long doubles should be used when available. more bits, more blessings ✨

"usemultiplicity"

From usemultiplicity.U:

conditionally defines the MULTIPLICITY symbol, and indicates Perl should be built to use multiplicity. it's giving main-character perl — multiple of everything 😌

"usemymalloc"

From mallocsrc.U:

contains y if the malloc that comes with this package is desired over the system's version of malloc. people often include special versions of malloc for efficiency, but ngl such versions are often less portable. see also mallocsrc and mallocobj.

and if this is y, then -lmalloc is removed from $libs. important detail, don't forget it 💜

"usenm"

From usenm.U:

contains "true" or "false" depending on whether the nm extraction is wanted or not. binary yes/no, no maybe 💅

"usensgetexecutablepath"

From usensgetexecutablepath.U:

this symbol, if defined, indicates that we can use _NSGetExecutablePath and realpath to get a full path for the executable — and hence convert $^X to an absolute path. macOS besties, this is for you 🍓

"useopcode"

From Extensions.U:

holds either "true" or "false", indicating whether the Opcode extension should be used. the sole use for this currently is giving users an easy mechanism to skip the Opcode extension from the Configure command line. practical and cute 🎀

"useperlio"

From useperlio.U:

conditionally defines the USE_PERLIO symbol, and indicates the PerlIO abstraction should be used throughout. throughout, bestie. all of it 🌈

"useposix"

From Extensions.U:

holds either "true" or "false", indicating whether the POSIX extension should be used. the sole use for this currently is to let hints files say that POSIX will not compile on a particular system. teamwork, kind of 🫶

"usequadmath"

From usequadmath.U:

conditionally defines the USE_QUADMATH symbol, indicating the quadmath library __float128 long doubles should be used when available. that's a lot of precision, and we're obsessed 💜

"usereentrant"

From usethreads.U:

conditionally defines the USE_REENTRANT_API symbol, which indicates the thread code may try to use the various _r versions of library functions.

⚠️ this is only potentially meaningful if usethreads is set — and it's very experimental. it's not even prompted for. you didn't hear it from me 🙈

"userelocatableinc"

From bin.U:

set to true to indicate that perl should relocate @"INC" entries at runtime based on the path to the perl binary.

any @"INC" paths starting .../ get relocated relative to the directory containing the perl binary, and then a logical cleanup of the path is made around the join point (removing dir/../ pairs). tidy little relocation moment ✨

"useshrplib"

From libperl.U:

set to "true" if the user wants to build a shared libperl, and "false" otherwise. that's the whole decision tree 🎀

"usesitecustomize"

From d_sitecustomize.U:

set to true when the user requires a mechanism that lets the sysadmin add entries to @"INC" at runtime. when this variable is set, it makes perl run $sitelib/sitecustomize.pl at startup. sysadmin customization era 👑

"usesocks"

From usesocks.U:

conditionally defines the USE_SOCKS symbol, indicating Perl should be built to use "SOCKS". socks on, besties 🧦

"usethreads"

From usethreads.U:

conditionally defines the USE_THREADS symbol, indicating Perl should be built to use threads. threading, but the classic flavor 🧵

"usevendorprefix"

From vendorprefix.U:

tells you whether the vendorprefix — and consequently the other vendor* paths — are in use. vendor girlies, check in 💅

"useversionedarchname"

From archname.U:

indicates whether to include $api_versionstring as a component of $archname. version it up ⭐

"usevfork"

From d_vfork.U:

set to true when the user accepts to use vfork. it's set to false when no vfork is available, or when the user explicitly requests not to use vfork. consent-based syscall usage, we love to see it 🫶

"usrinc"

From usrinc.U:

holds the path of the include files, which is usually /usr/include. it's mainly used by other Configure units. classic path, iconic location 🎀

"uuname"

From Loc.U:

this variable is defined but not used by Configure. the value is the empty string and is not useful. it's giving ghost variable 👻

"uvXUformat"

From perlxvf.U:

the format string used for printing a Perl UV as an unsigned hexadecimal integer in uppercase ABCDEF. uppercase hex, uppercase energy 🔥

"uvoformat"

From perlxvf.U:

the format string used for printing a Perl UV as an unsigned octal integer. octal representation, slay 🐙

"uvsize"

From perlxv.U:

the size of a UV in bytes. yes, in bytes. always in bytes 💅

"uvtype"

From perlxv.U:

the C type used for Perl's UV. the actual type name, no cap ✨

"uvuformat"

From perlxvf.U:

the format string used for printing a Perl UV as an unsigned decimal integer. decimal, unsigned, done 🌸

"uvxformat"

From perlxvf.U:

the format string used for printing a Perl UV as an unsigned hexadecimal integer in lowercase abcdef. lowercase hex besties, this is your moment 🦋

v

"vendorarch"

From vendorarch.U:

This variable contains the value of the PERL_VENDORARCH symbol, and yes bestie it may have a ~ on the front. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place their own architecture-dependent modules and extensions in this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or equivalent. See INSTALL for details.

`vendorarchexp`

From vendorarch.U:

This variable is the ~name expanded version of vendorarch, so that you may use it directly in Makefiles or shell scripts.

`vendorbin`

From vendorbin.U:

This variable contains the eventual value of the VENDORBIN symbol. It may have a ~ on the front. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place additional binaries in this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or equivalent. See INSTALL for details.

`vendorbinexp`

From vendorbin.U:

This variable is the ~name expanded version of vendorbin, so that you may use it directly in Makefiles or shell scripts.

`vendorhtml1dir`

From vendorhtml1dir.U:

This variable contains the name of the directory for html pages. It may have a ~ on the front. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place their own html pages in this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or equivalent. See INSTALL for details.

`vendorhtml1direxp`

From vendorhtml1dir.U:

This variable is the ~name expanded version of vendorhtml1dir, so that you may use it directly in Makefiles or shell scripts.

`vendorhtml3dir`

From vendorhtml3dir.U:

This variable contains the name of the directory for html library pages. It may have a ~ on the front. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place their own html pages for modules and extensions in this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or equivalent. See INSTALL for details.

`vendorhtml3direxp`

From vendorhtml3dir.U:

This variable is the ~name expanded version of vendorhtml3dir, so that you may use it directly in Makefiles or shell scripts.

`vendorlib`

From vendorlib.U:

This variable contains the eventual value of the VENDORLIB symbol, which is the name of the private library for this package. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place their own modules in this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or equivalent. See INSTALL for details.

`vendorlib_stem`

From vendorlib.U:

This variable is $vendorlibexp with any trailing version-specific component removed. The elements in inc_version_list (inc_version_list.U) can be tacked onto this variable to generate a list of directories to search.

`vendorlibexp`

From vendorlib.U:

This variable is the ~name expanded version of vendorlib, so that you may use it directly in Makefiles or shell scripts.

`vendorman1dir`

From vendorman1dir.U:

This variable contains the name of the directory for man1 pages. It may have a ~ on the front. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place their own man1 pages in this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or equivalent. See INSTALL for details.

`vendorman1direxp`

From vendorman1dir.U:

This variable is the ~name expanded version of vendorman1dir, so that you may use it directly in Makefiles or shell scripts.

`vendorman3dir`

From vendorman3dir.U:

This variable contains the name of the directory for man3 pages. It may have a ~ on the front. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place their own man3 pages in this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or equivalent. See INSTALL for details.

`vendorman3direxp`

From vendorman3dir.U:

This variable is the ~name expanded version of vendorman3dir, so that you may use it directly in Makefiles or shell scripts.

`vendorprefix`

From vendorprefix.U:

This variable holds the full absolute path of the directory below which the vendor will install add-on packages. See INSTALL for usage and examples.

`vendorprefixexp`

From vendorprefix.U:

This variable holds the full absolute path of the directory below which the vendor will install add-on packages. Derived from vendorprefix.

`vendorscript`

From vendorscript.U:

This variable contains the eventual value of the VENDORSCRIPT symbol. It may have a ~ on the front. The standard distribution will put nothing in this directory. Vendors who distribute perl may wish to place additional executable scripts in this directory with MakeMaker Makefile.PL "INSTALLDIRS"=vendor or equivalent. See INSTALL for details.

`vendorscriptexp`

From vendorscript.U:

This variable is the ~name expanded version of vendorscript, so that you may use it directly in Makefiles or shell scripts.

`version`

From patchlevel.U:

The full version number of this package, such as 5.6.1 (or 5_6_1). This combines revision, patchlevel, and subversion to get the full version number, including any possible subversions. This is suitable for use as a directory name, and hence is filesystem dependent.

`version_patchlevel_string`

From patchlevel.U:

This is a string combining version, subversion and perl_patchlevel (if perl_patchlevel is non-zero). It is typically something like 'version 7 subversion 1' or 'version 7 subversion 1 patchlevel 11224' It is computed here to avoid duplication of code in myconfig.SH and lib/Config.pm.

`versiononly`

From versiononly.U:

If set, this symbol indicates that only the version-specific components of a perl installation should be installed. This may be useful for making a test installation of a new version without disturbing the existing installation. Setting versiononly is equivalent to setting installperl's -v option. In particular, the non-versioned scripts and programs such as a2p, c2ph, h2xs, pod2*, and perldoc are not installed (see INSTALL for a more complete list). Nor are the man pages installed. Usually, this is undef.

`vi`

From Loc.U:

This variable is defined but not used by Configure. The value is the empty string and is not useful.

x ✨

`xlibpth`

From libpth.U:

This variable holds extra path (space-separated) used to find libraries on this platform, for example CPU-specific libraries (on multi-CPU platforms) may be listed here.

`xlocale_needed`

From d_newlocale.U:

This symbol, if defined, indicates that the C program should include <xlocale.h> to get newlocale() and its friends.

y 🎀

`yacc`

From yacc.U:

This variable holds the name of the compiler compiler we want to use in the Makefile. It can be yacc, byacc, or bison -y.

`yaccflags`

From yacc.U:

This variable contains any additional yacc flags desired by the user. It is up to the Makefile to use this.

z 🦋

`zcat`

From Loc.U:

This variable is defined but not used by Configure. The value is the empty string and is not useful.

`zip`

From Loc.U:

This variable is used internally by Configure to determine the full pathname (if any) of the zip program. After Configure runs, the value is reset to a plain "zip" and is not useful.

🦋 GIT DATA 🦋

Information on the git commit from which the current perl binary was compiled can be found in the variable $Config::Git_Data. The variable is a structured string that looks something like this:

git_commit_id='ea0c2dbd5f5ac6845ecc7ec6696415bf8e27bd52'
git_describe='GitLive-blead-1076-gea0c2db'
git_branch='smartmatch'
git_uncommitted_changes=''
git_commit_id_title='Commit id:'
git_commit_date='2009-05-09 17:47:31 +0200'

Its format is not guaranteed not to change over time.

🌸 NOTE 🌸

This module contains a good example of how to use tie to implement a cache and an example of how to make a tied variable readonly to those outside of it.

okay that's literally the whole page bestie 💖 this iconic little manual page is from perl v5.42.3, dated 2026-11-03, and it's Config(3pm). periodt ✨🫶

📦 where this page comes from

alpine 3.24: perl-doc 5.42.3-r0 · Artistic-1.0-Perl OR GPL-1.0-or-later
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on 2026-11-06: a language model's rewrite of the original, under its terms

Config(3pm)

🎀 Config(3pm) 🎀

✨ NAME ✨

✨ SYNOPSIS ✨

✨ DESCRIPTION ✨

the functions, bestie 🦋

✨ EXAMPLE ✨

⚠️ WARNING ⚠️

✨ GLOSSARY ✨

🌸 P 🌸

🌈 _ 🌈

🦋 a 🦋

b 🎀

c 🦋

cppflags

cpplast

cppminus

cpprun

cppstdin

cppsymbols

crypt_r_proto

cryptlib

csh

ctermid_r_proto

ctime_r_proto

🌸 d 🌸

d_Gconvert

d_PRIEUldbl

d_PRIFUldbl

d_PRIGUldbl

d_PRIXU64

d_PRId64

d_PRIeldbl

d_PRIfldbl

d_PRIgldbl

d_PRIi64

d_PRIo64

d_PRIu64

d_PRIx64

d_SCNfldbl

d__fwalk

d_accept4

d_access

d_accessx

d_acosh

d_aintl

d_alarm

d_archlib

d_asctime64

d_asctime_r

d_asinh

d_atanh

d_atolf

d_atoll

d_attribute_always_inline

d_attribute_deprecated

d_attribute_format

d_attribute_malloc

d_attribute_nonnull

d_attribute_noreturn

d_attribute_pure

🌸 "d_double_style_cray"

🦋 "d_double_style_ibm"

🎀 "d_double_style_ieee"

💜 "d_double_style_vax"

🧚 "d_drand48_r"

⭐ "d_drand48proto"

💖 "d_dup2"

🌈 "d_dup3"

🦋 "d_duplocale"

🍓 "d_eaccess"

🎀 "d_endgrent"

💜 "d_endgrent_r"

🌸 "d_endhent"

🧚 "d_endhostent_r"

⭐ "d_endnent"

🔥 "d_endnetent_r"

🦋 "d_endpent"

💖 "d_endprotoent_r"

🌈 "d_endpwent"

`cppflags`

`cpplast`

`cppminus`

`cpprun`

`cppstdin`

`cppsymbols`

`crypt_r_proto`

`cryptlib`

`csh`

`ctermid_r_proto`

`ctime_r_proto`

`d_Gconvert`

`d_PRIEUldbl`

`d_PRIFUldbl`

`d_PRIGUldbl`

`d_PRIXU64`

`d_PRId64`

`d_PRIeldbl`

`d_PRIfldbl`

`d_PRIgldbl`

`d_PRIi64`

`d_PRIo64`

`d_PRIu64`

`d_PRIx64`

`d_SCNfldbl`

`d__fwalk`

`d_accept4`

`d_access`

`d_accessx`

`d_acosh`

`d_aintl`

`d_alarm`

`d_archlib`

`d_asctime64`

`d_asctime_r`

`d_asinh`

`d_atanh`

`d_atolf`

`d_atoll`

`d_attribute_always_inline`

`d_attribute_deprecated`

`d_attribute_format`

`d_attribute_malloc`

`d_attribute_nonnull`

`d_attribute_noreturn`

`d_attribute_pure`

🌸 `"d_double_style_cray"`

🦋 `"d_double_style_ibm"`

🎀 `"d_double_style_ieee"`

💜 `"d_double_style_vax"`

🧚 `"d_drand48_r"`

⭐ `"d_drand48proto"`

💖 `"d_dup2"`

🌈 `"d_dup3"`

🦋 `"d_duplocale"`

🍓 `"d_eaccess"`

🎀 `"d_endgrent"`

💜 `"d_endgrent_r"`

🌸 `"d_endhent"`

🧚 `"d_endhostent_r"`

⭐ `"d_endnent"`

🔥 `"d_endnetent_r"`

🦋 `"d_endpent"`

💖 `"d_endprotoent_r"`

🌈 `"d_endpwent"`

🍓 `"d_endpwent_r"`

🎀 `"d_endsent"`

💜 `"d_endservent_r"`

🧚 `"d_eofnblk"`

⭐ `"d_erf"`

🔥 `"d_erfc"`

🌸 `"d_eunice"`

🦋 `"d_exp2"`

🎀 `"d_expm1"`

💜 `"d_faststdio"`

🍓 `"d_fchdir"`

🌈 `"d_fchmod"`

⭐ `"d_fchmodat"`

🧚 `"d_fchown"`

💖 `"d_fcntl"`