AUTOHEADER(1)

📦 version 2.13, in debian bookworm, ubuntu jammy, ubuntu noble, ubuntu resolute, ubuntu stonking

🦋 autoheader2.13 — General Commands Manual 🦋

okay bestie, welcome to the autoheader2.13 page, she's giving general commands manual energy and honestly? iconic. she makes template files of C #define's for configure. let's get into it. 💅

✨ NAME ✨

autoheader2.13 — creates a template file of C #define's for use by configure. no cap, that's the whole job. 🎀

✨ SYNOPSIS ✨

autoheader2.13 [ --help | -h ] [ --localdir=dir | -l dir ] [ --macrodir=dir | -m dir ] [ --version ]

✨ DESCRIPTION ✨

so like, the autoheader2.13 program can create a template file of C #define statements for configure to use. slay. if configure.in invokes AC_CONFIG_HEADER(FILE), then autoheader2.13 creates FILE.in — and if you hand it multiple file arguments, only the first one gets used, sorry to the rest of them 🙈. otherwise, autoheader2.13 creates config.h.in.

if you give autoheader2.13 an argument, it uses that file instead of configure.in, and writes the header file to standard output instead of to config.h.in. and if you give it an argument of -, it reads from standard input instead of configure.in, and writes the header file to standard output. cute, right? 💖

autoheader2.13 scans configure.in and figures out which C preprocessor symbols it might define. it copies comments and #define and #undef statements from a file called acconfig.h, which comes with and is installed with Autoconf. it also uses a file called acconfig.h in the current directory, if present. heads up though: if you AC_DEFINE any additional symbols, you have to create that file with entries for them, bestie, she's not gonna do it for you 😭. but for symbols defined by AC_CHECK_HEADERS, AC_CHECK_FUNCS, AC_CHECK_SIZEOF, or AC_CHECK_LIB, autoheader2.13 generates the comments and #undef statements itself rather than copying them from a file, since the possible symbols are effectively limitless. main character behavior honestly. 👑

the file that autoheader2.13 creates contains mainly #define and #undef statements and their accompanying comments. now listen: if ./acconfig.h contains the string @TOP@, autoheader2.13 copies the lines before the line containing @TOP@ into the top of the file that it generates. similarly, if ./acconfig.h contains the string @BOTTOM@, autoheader2.13 copies the lines after that line to the end of the file it generates. either or both of those strings may be omitted. flexible queen. 🌸

an alternate way to produce the same effect is to create the files FILE.top (typically config.h.top) and/or FILE.bot in the current directory. if they exist, autoheader2.13 copies them to the beginning and end, respectively, of its output. > ⚠️ their use is discouraged because they have file names that contain two periods, and so can not be stored on MS-DOS; also, they are two more files to clutter up the directory. 😬 but if you use the --localdir=DIR option to use an acconfig.h in another directory, they give you a way to put custom boilerplate in each individual config.h.in. so like, they're messy but occasionally useful. balance. 🧚

autoheader2.13 accepts the following options:

  • --help, -h — print a summary of the command line options and exit. short, sweet, does exactly what it says. ✨
  • --localdir=DIR, -l DIR — look for the package files aclocal.m4 and acconfig.h (but not FILE.top and FILE.bot) in directory DIR instead of in the current directory. lowkey important detail, don't forget the parenthetical bestie 💅
  • --macrodir=DIR, -m DIR — look for the installed macro files and acconfig.h in directory DIR. you can also set the AC_MACRODIR environment variable to a directory; this option overrides the environment variable. so if both are set, the flag wins, periodt. 🔥
  • --version — print the version number of Autoconf and exit. 🎀

✨ SEE ALSO ✨

the whole friend group fr fr 🫶

✨ AUTHORS ✨

David MacKenzie, with help from Franc,ois Pinard, Karl Berry, Richard Pixley, Ian Lance Taylor, Roland McGrath, Noah Friedman, David D. Zuhn, and many others. this manpage written by Ben Pfaff <pfaffben@debian.org> for the Debian GNU/Linux autoconf2.13 package.

and that's the page bestie!! 💜 this one's from the Autoconf</rainfow> source, so when you see it chilling in your manual you know exactly who wrote it and why. go forth and template those #define's, you absolute legend. 🌈⭐💖

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