PERLPOD(1perl)

📦
version 5.44.0 · 2 versions
, in arch rolling

💖 PERLPOD(1perl) 💖

the Plain Old Documentation format — from the Perl Programmers Reference Guide 🫶

🌸 NAME 🌸

perlpod — the Plain Old Documentation format

✨ DESCRIPTION ✨

Pod is a simple-to-use markup language for writing documentation for Perl, Perl programs, and Perl modules. It's literally made for docs, bestie.

Translators exist that convert Pod to all kinds of formats like plain text, HTML, man pages, and more. Slay.

Pod markup has three basic kinds of paragraphs: ordinary, verbatim, and command. Periodt.

🦋 Ordinary Paragraph 🦋

Most paragraphs in your documentation are gonna be ordinary blocks of text, like this one. You can just type your text with no markup whatsoever, and with just a blank line before and after. When it gets formatted, it gets minimal formatting: rewrapped, probably put into a proportionally spaced font, and maybe even justified. Iconic.

You can use formatting codes in ordinary paragraphs for bold, italic, "code-style", hyperlinks, and more. Those codes are explained in the "Formatting Codes" section below, iykyk.

🧚 Verbatim Paragraph 🧚

Verbatim paragraphs are usually used for presenting a codeblock or other text that doesn't need any special parsing or formatting, and that shouldn't be wrapped.

A verbatim paragraph is distinguished by having its first character be a space or a tab. (And commonly, all its lines begin with spaces and/or tabs.) It should be reproduced exactly, with tabs assumed to be on 8-column boundaries. There are no special formatting codes, so you can't italicize or anything like that. A \ means \, and nothing else. That's it, fr fr.

👑 Command Paragraph 👑

A command paragraph is used for special treatment of whole chunks of text, usually as headings or parts of lists.

All command paragraphs (which are typically only one line long) start with =, followed by an identifier, followed by arbitrary text that the command can use however it pleases. Currently recognized commands are:

=pod
=head1 Heading Text
=head2 Heading Text
=head3 Heading Text
=head4 Heading Text
=head5 Heading Text
=head6 Heading Text
=over indentlevel
=item stuff
=back
=begin format
=end format
=for format text...
=encoding type
=cut

To explain them each in detail:

🌈 =head1 Heading Text through =head6 Heading Text 🌈

Head1 through head6 produce headings, head1 being the highest level. The text in the rest of this paragraph is the content of the heading. For example:

=head2 Object Attributes

The text Object Attributes comprises the heading there. The text in these heading commands can use formatting codes, as seen here:

=head2 Possible Values for C<$/>

Such commands are explained in the "Formatting Codes" section, below.

Note that head5 and head6 were introduced in 2020 and in Pod::Simple 3.41, released in October 2020, so they might not be supported on the Pod parser you use.

💅 =over indentlevel, =item stuff..., =back 💅

Item, over, and back require a little more explanation: =over starts a region specifically for the generation of a list using =item commands, or for indenting (groups of) normal paragraphs. At the end of your list, use =back to end it. The indentlevel option to =over indicates how far over to indent, generally in ems (where one em is the width of an "M" in the document's base font) or roughly comparable units; if there is no indentlevel option, it defaults to four. (And some formatters may just ignore whatever indentlevel you provide.) In the stuff in =item stuff..., you may use formatting codes, as seen here:

=item Using C<$|> to Control Buffering

Such commands are explained in the "Formatting Codes" section, below.

Note also that there are some basic rules to using =over ... =back regions:

  • Don't use =items outside of an =over ... =back region.
  • The first thing after the =over command should be an =item, unless there aren't going to be any items at all in this =over ... =back region.
  • Don't put =headn commands inside an =over ... =back region.
  • And perhaps most importantly, keep the items consistent: either use =item * for all of them, to produce bullets; or use =item 1., =item 2., etc., to produce numbered lists; or use =item foo, =item bar, etc.--namely, things that look nothing like bullets or numbers. (If you have a list that contains both: 1) things that don't look like bullets nor numbers, plus 2) things that do, you should preface the bullet- or number-like items with Z<>. See Z<> below for an example.)

If you start with bullets or numbers, stick with them, as formatters use the first =item type to decide how to format the list.

💀 =cut 💀

To end a Pod block, use a blank line, then a line beginning with =cut, and a blank line after it. This lets Perl (and the Pod formatter) know that this is where Perl code is resuming. (The blank line before the =cut is not technically necessary, but many older Pod processors require it.)

✨ =pod ✨

The =pod command by itself doesn't do much of anything, but it signals to Perl (and Pod formatters) that a Pod block starts here. A Pod block starts with any command paragraph, so a =pod command is usually used just when you want to start a Pod block with an ordinary paragraph or a verbatim paragraph. For example:

=item stuff()

This function does stuff.

=cut

sub stuff {
  ...
}

=pod

Remember to check its return value, as in:

  stuff() || die "Couldn't do stuff!";

=cut

🎀 =begin formatname, =end formatname, =for formatname text... 🎀

For, begin, and end will let you have regions of text/code/data that are not generally interpreted as normal Pod text, but are passed directly to particular formatters, or are otherwise special. A formatter that can use that format will use the region, otherwise it will be completely ignored.

A command =begin formatname, some paragraphs, and a command =end formatname, mean that the text/data in between is meant for formatters that understand the special format called formatname. For example,

=begin html

<hr> <img src="thang.png">
<p> This is a raw HTML paragraph </p>

=end html

The command =for formatname text... specifies that the remainder of just this paragraph (starting right after formatname) is in that special format.

=for html <hr> <img src="thang.png">
<p> This is a raw HTML paragraph </p>

This means the same thing as the above =begin html ... =end html region.

That is, with =for, you can have only one paragraph's worth of text (i.e., the text in =foo targetname text...), but with =begin targetname ... =end targetname, you can have any amount of stuff in between. (Note that there still must be a blank line after the =begin command and a blank line before the =end command.)

Here are some examples of how to use these:

=begin html

<br>Figure 1.<br><IMG SRC="figure1.png"><br>

=end html

=begin text

  ---------------
  |  foo        |
  |        bar  |
  ---------------

^^^^ Figure 1. ^^^^

=end text

Some format names that formatters currently are known to accept include "roff", "man", "latex", "tex", "text", and "html". (Some formatters will treat some of these as synonyms.)

A format name of "comment" is common for just making notes (presumably to yourself) that won't appear in any formatted version of the Pod document:

=for comment
Make sure that all the available options are documented!

Some formatnames will require a leading colon (as in =for :formatname, or =begin :formatname ... =end :formatname), to signal that the text is not raw data, but instead is Pod text (i.e., possibly containing formatting codes) that's just not for normal formatting (e.g., may not be a normal-use paragraph, but might be for formatting as a footnote).

🌟 =encoding encodingname 🌟

This command is used for declaring the encoding of a document. Most users won't need this; but if your encoding isn't US-ASCII, then put a =encoding encodingname command very early in the document so that pod formatters will know how to decode the document. For encodingname, use a name recognized by the Encode::Supported module. Some pod formatters may try to guess between a Latin-1 or CP-1252 versus UTF-8 encoding, but they may guess wrong. It's best to be explicit if you use anything besides strict ASCII. Examples:

=encoding latin1

=encoding utf8

=encoding koi8-r

=encoding ShiftJIS

=encoding big5

=encoding affects the whole document, and must occur only once.

And don't forget, all commands but =encoding last up until the end of its paragraph, not its line. So in the examples below, you can see that every command needs the blank line after it, to end its paragraph. (And some older Pod translators may require the =encoding line to have a following blank line as well, even though it should be legal to omit.)

Some examples of lists include:

=over

=item *

First item

=item *

Second item

=back

=over

=item Foo()

Description of Foo function

=item Bar()

Description of Bar function

=back

🎀 Formatting Codes 🎀

In ordinary paragraphs and in some command paragraphs, various formatting codes (a.k.a. "interior sequences") can be used:

I<text> -- italic text

Used for emphasis (""be I<careful!>"") and parameters (""redo I<LABEL>"")

B<text> -- bold text

Used for switches (""perl's B<-n> switch""), programs (""some systems provide a B<chfn> for that""), emphasis (""be B<careful!>""), and so on (""and that feature is known as B<autovivification>"").

"U<text>" — underline text 💅

Okay so this one is new new — like, added in 2024 — so it might not be in every processor or output format yet, bestie. Not every renderer got the memo. 😭

And real talk: some output formats literally cannot produce both italic and underline formatting at the same time. So even if both get recognized, they might not even look different from each other. Visually identical. Tragic.

"C<code>" — code text 🖥️

This renders stuff in a typewriter font, or gives you some other lil signal that "hey, this is program text" (C<gmtime($^T)>) or some other form of computerese (C<drwxr-xr-x>). It's giving "this is code, bestie." ✨

There are a bunch of different syntaxes for this one, all listed below. In all of the syntaxes given here, text, name, and section cannot contain the characters '/' and '|' — and any < or > should be matched up. 🫶

  • "L<name>"
    • Link to a Perl manual page (e.g., "L<Net::Ping>"). Heads up: name should not contain spaces. This syntax is also occasionally used for references to Unix man pages, as in "L<crontab(5)>".
  • "L<name/"sec">" or "L<name/sec>"
    • Link to a section in another manual page. E.g., "L<perlsyn/"For Loops">"
  • "L</"sec">" or "L</sec>"
    • Link to a section in this manual page. E.g., "L</"Object Methods">"

A section gets started by the named heading or item. For example, "L<perlvar/$.>" and "L<perlvar/"$.">" both link to the section started by "=item $." in perlvar. And "L<perlsyn/For Loops>" and "L<perlsyn/"For Loops">" both link to the section started by "=head2 For Loops" in perlsyn. Same destination, different glow-up. 🌈

To control what text is used for display, you use "L<text|...>", as in:

  • "L<text|name>"
    • Link this text to that manual page. E.g., "L<Perl Error Messages|perldiag>"
  • "L<text|name/"sec">" or "L<text|name/sec>"
    • Link this text to that section in that manual page. E.g., "L<postfix "if"|perlsyn/"Statement Modifiers">"
  • "L<text|/"sec">" or "L<text|/sec>" or "L<text|"sec">"
    • Link this text to that section in this manual page. E.g., "L<the various attributes|/"Member Data">"

Or you can link to a web page:

"E<escape>" — a character escape 🪄

Super similar to those HTML/XML "&foo;" "entity references," if you've met those before:

  • "E<lt>" — a literal < (less than)
  • "E<gt>" — a literal > (greater than)
  • "E<verbar>" — a literal | (vertical bar)
  • "E<sol>" — a literal / (solidus)
The above four are optional except in other formatting codes, notably "L<...>", and when preceded by a capital letter.
  • "E<htmlname>"
    • Some non-numeric HTML entity name, such as "E<eacute>", meaning the same thing as "&eacute;" in HTML — i.e., a lowercase e with an acute (/-shaped) accent.
  • "E<number>"
    • The ASCII/Latin-1/Unicode character with that number. A leading "0x" means that number is hex, as in "E<0x201E>". A leading "0" means that number is octal, as in "E<075>". Otherwise number is interpreted as being in decimal, as in "E<181>".
Ngl, older Pod formatters might not recognize octal or hex numeric escapes at all, and many formatters cannot reliably render characters above 255. Some formatters may even have to use compromised renderings of Latin-1/CP-1252 characters, like rendering "E<eacute>" as just a plain "e". So like… manage your expectations. 🙈

"F<filename>" — used for filenames 📁

Typically displayed in italics. Example: "F<.cshrc>"

"S<text>" — text contains non-breaking spaces 🚫

This means that the words in text should not be broken across lines. Example: "S<$x ? $y : $z>".

"X<topic name>" — an index entry 🗂️

This is ignored by most formatters, but some may use it for building indexes. It always renders as empty-string. Example: "X<absolutizing relative URLs>"

"Z<>" — a null (zero-effect) formatting code 👻

This one is rarely used. It's one way to get around using an E<...> code sometimes. For example, instead of "NE<lt>3" (for "N<3") you could write "NZ<><3" — the "Z<>" breaks up the "N" and the "<" so they can't be considered the part of a (fictitious) "N<...>" code. It's giving chaos gremlin but make it polite. ✨

Another use is to indicate that stuff in "=item Z<>stuff..." is not to be considered to be a bullet or number. For example, without the "Z<>", the line

=item Z<>500 Server error

could possibly be parsed as an item in a numbered list when it isn't meant to be. Rude, honestly.

Still another use is to maintain visual space between "=item" lines. If you specify

=item foo

=item bar

it will typically get rendered as

foo
bar

That may be what you want, but if what you really want is

foo

bar

you can use "Z<>" to accomplish that

=item foo

Z<>

=item bar

Most of the time, you will need only a single set of angle brackets to delimit the beginning and end of formatting codes. However, sometimes you will want to put a real right angle bracket (a greater-than sign, '>') inside of a formatting code. This is particularly common when using a formatting code to provide a different font-type for a snippet of code. And as with all things in Perl, there is more than one way to do it. 😌

One way is to simply escape the closing bracket using an "E" code:

C<$a E<lt>=E<gt> $b>

This will produce: "$a <=> $b"

A more readable, and perhaps more "plain" way is to use an alternate set of delimiters that doesn't require a single ">" to be escaped. Doubled angle brackets ("<<" and ">>") may be used if and only if there is whitespace right after the opening delimiter and whitespace right before the closing delimiter! If and only if, bestie. This is not a suggestion. For example, the following will do the trick:

C<< $a <=> $b >>

In fact, you can use as many repeated angle-brackets as you like, so long as you have the same number of them in the opening and closing delimiters, and you make sure that whitespace immediately follows the last '<' of the opening delimiter, and immediately precedes the first '>' of the closing delimiter. (The whitespace is ignored.) So the following will also work:

C<<< $a <=> $b >>>
C<<<<  $a <=> $b     >>>>

And they all mean exactly the same as this:

C<$a E<lt>=E<gt> $b>

The multiple-bracket form does not affect the interpretation of the contents of the formatting code — only how it must end. That means that the examples above are also exactly the same as this:

C<< $a E<lt>=E<gt> $b >>

As a further example, this means that if you wanted to put these bits of code in "C" (code) style:

open(X, ">>thing.dat") || die $!
$foo->bar();

you could do it like so:

C<<< open(X, ">>thing.dat") || die $! >>>
C<< $foo->bar(); >>

which is presumably easier to read than the old way:

C<open(X, "E<gt>E<gt>thing.dat") || die $!>
C<$foo-E<gt>bar();>

This is currently supported by pod2text (Pod::Text), pod2man (Pod::Man), and any other pod2xxx or Pod::Xxxx translators that use Pod::Parser 1.093 or later, or Pod::Tree 1.02 or later. 📚

🌸 The Intent 🌸

The intent is simplicity of use, not power of expression. Periodt. ✨

Paragraphs look like paragraphs (block format), so that they stand out visually, and so that I could run them through "fmt" easily to reformat them (that's F7 in my version of vi, or Esc Q in my version of emacs). I wanted the translator to always leave the "'" and "`" and """ quotes alone, in verbatim mode, so I could slurp in a working program, shift it over four spaces, and have it print out, er, verbatim. And presumably in a monospace font. 👑

The Pod format is not necessarily sufficient for writing a book. Pod is just meant to be an idiot-proof common source for nroff, HTML, TeX, and other markup languages, as used for online documentation. Translators exist for pod2text, pod2html, pod2man (that's for nroff(1) and troff(1)), pod2latex, and pod2fm. Various others are available in CPAN. 🌈

🫶 Embedding Pods in Perl Modules 🫶

You can embed Pod documentation in your Perl modules and scripts. Start your documentation with an empty line, a "=head1" command at the beginning, and end it with a "=cut" command and an empty line. The perl executable will ignore the Pod text. 🧚

You can place a Pod statement where perl expects the beginning of a new statement, but not within a statement, as that would result in an error. See any of the supplied library modules for examples.

If you're going to put your Pod at the end of the file, and you're using an "__END__" or "__DATA__" cut mark, make sure to put an empty line there before the first Pod command.

__END__

=head1 NAME

Time::Local - efficiently compute time from local and GMT time

Without that empty line before the "=head1", many translators wouldn't have recognized the "=head1" as starting a Pod block. So don't skip it, love. 😭

💜 Hints for Writing Pod 💜

  • The podchecker command is provided for checking Pod syntax for errors and warnings. For example, it checks for completely blank lines in Pod blocks and for unknown commands and formatting codes. You should still also pass your document through one or more translators and proofread the result, or print out the result and proofread that. Some of the problems found may be bugs in the translators, which you may or may not wish to work around. 🔍
  • If you're more familiar with writing in HTML than with writing in Pod, you can try your hand at writing documentation in simple HTML, and converting it to Pod with the experimental Pod::HTML2Pod module, (available in CPAN), and looking at the resulting code. The experimental Pod::PXML module in CPAN might also be useful. 🎀
  • Many older Pod translators require the lines before every Pod command and after every Pod command (including "=cut"!) to be a blank line. Having something like this:
# - - - - - - - - - - - -
=item $firecracker->boom()

This noisily detonates the firecracker object.
=cut
sub boom {
...

...will make such Pod translators completely fail to see the Pod block at all. 💀

Instead, have it like this:

# - - - - - - - - - - - -

=item $firecracker->boom()

This noisily detonates the firecracker object.

=cut

sub boom {
...
  • Some older Pod translators are lowkey picky about paragraph breaks. They need paragraphs (yes, even command paragraphs like =head2 Functions) to be separated by lines that are completely empty. So if you got an "empty" line that's actually got some spaces chilling on it 🙈, that might not count as a separator for those translators, and bestie, that leads to some truly cursed formatting.
  • Older translators might wrap extra words around an L<> link. Like, L<Foo::Bar> could come out as "the Foo::Bar manpage", for example ✨. So don't write stuff like "the L<foo> documentation" if you want the translated doc to actually read sensibly, iykyk. Instead write "the L<Foo::Bar|Foo::Bar> documentation" or "L<the Foo::Bar documentation|Foo::Bar>", so you're the one controlling how the link comes out. main character energy: you decide the output 💅
  • Past column 70 in a verbatim block? Risky. Some formatters might just ungracefully wrap that for you 😭. Keep it under 70 and you're golden 🫶

📚 SEE ALSO 📚

  • perlpodspec
  • "PODs: Embedded Documentation" in perlsyn
  • perlnewmod
  • perldoc
  • pod2html
  • pod2man
  • podchecker

✨ AUTHOR ✨

Larry Wall, Sean M. Burke 💖

And that's a wrap on the whole page, bestie! 🎀 This gorgeousness ships as perl v5.44.0, dated 2026-10-17, and lives in the manpage neighborhood as PERLPOD(1perl) 🌈👑 Go forth and write immaculate Pod, fr fr 🦋🌸

📦 where this page comes from