perlpod - plain old documentation
A pod-to-whatever translator reads a pod file paragraph by paragraph, and
translates it to the appropriate output format. There are three kinds of
o A verbatim paragraph, distinguished by being indented (that is, it
starts with space or tab). It should be reproduced exactly, with
tabs assumed to be on 8-column boundaries. There are no special
formatting escapes, so you can't italicize or anything like that. A
\ means \, and nothing else.
o A command. All command paragraphs start with "=", followed by an
identifier, followed by arbitrary text that the command can use
however it pleases. Currently recognized commands are
The "=pod" directive does nothing beyond telling the compiler to lay
off parsing code through the next "=cut". It's useful for adding
another paragraph to the doc if you're mixing up code and pod a lot.
Head1 and head2 produce first and second level headings, with the
text in the same paragraph as the "=headn" directive forming the
Item, over, and back require a little more explanation: "=over"
starts a section specifically for the generation of a list using
"=item" commands. At the end of your list, use "=back" to end it. You
will probably want to give "4" as the number to "=over", as some
formatters will use this for indentation. This should probably be a
default. Note also that there are some basic rules to using =item:
don't use them outside of an =over/=back block, use at least one
inside an =over/=back block, you don't _have_ to include the =back if
the list just runs off the document, 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., i.e., things
that looks nothing like bullets or numbers. If you start with bullets
or numbers, stick with them, as many formatters use the first "=item"
type to decide how to format the list.
For, begin, and end let you include sections that are not interpreted
as pod text, but passed directly to particular formatters. A
formatter that can utilize that format will use the section,
otherwise it will be completely ignored. The directive "=for"
specifies that the entire next paragraph is in the format indicated
by the first word after "=for", like this:
=for html <br>
<p> This is a raw HTML paragraph </p>
The paired commands "=begin" and "=end" work very similarly to
"=for", but instead of only accepting a single paragraph, all text
from "=begin" to a paragraph with a matching "=end" are treated as a
Here are some examples of how to use these:
<br>Figure 1.<IMG SRC="figure1.png"><br>
| foo |
| bar |
^^^^ Figure 1. ^^^^
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.)
And don't forget, when using any command, that the command lasts up
until the end of the paragraph, not the line. Hence in the examples
below, you can see the empty lines after each command to end its
Some examples of lists include:
Description of Foo function
Description of Bar function
o An ordinary block of text. It will be filled, and maybe even
justified. Certain interior sequences are recognized both here and
I<text> italicize text, used for emphasis or variables
B<text> embolden text, used for switches and programs
S<text> text contains non-breaking spaces
C<code> literal code
L<name> A link (cross reference) to name
L<name> manual page
L<name/ident> item in manual page
L<name/"sec"> section in other manual page
L<"sec"> section in this manual page
(the quotes are optional)
F<file> Used for filenames
X<index> An index entry
Z<> A zero-width character
E<escape> A named character (very similar to HTML escapes)
E<lt> A literal <
E<gt> A literal >
(these are optional except in other interior
sequences and when preceded by a capital letter)
E<n> Character number n (probably in ASCII)
E<html> Some non-numeric HTML entity, such
That's it. The intent is simplicity, not power. I wanted paragraphs to
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). I wanted the translator (and not me) to worry
about whether " or ' is a left quote or a right quote within filled text,
and I wanted it to leave the quotes alone, dammit, in verbatim mode, so I
could slurp in a working program, shift it over 4 spaces, and have it
print out, er, verbatim. And presumably in a constant width font.
In particular, you can leave things like this verbatim in your text:
Doubtless a few other commands or sequences will need to be added along
the way, but I've gotten along surprisingly well with just these.
Note that I'm not at all claiming this to be sufficient for producing a
book. I'm just trying to make an idiot-proof common source for nroff,
TeX, and other markup languages, as used for online documentation.
Translators exist for pod2man (that's for nrof
pod2html, pod2latex, and pod2fm.
Embedding Pods in Perl Modules [Toc] [Back]
You can embed pod documentation in your Perl scripts. Start your
documentation with a "=head1" command at the beginning, and end it with a
"=cut" command. Perl will ignore the pod text. See any of the supplied
library modules for examples. If you're going to put your pods 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 directive.
modern - I am a modern module
If you had not had that empty line there, then the translators wouldn't
have seen it.
o Pod translators usually will require paragraphs to be separated by
completely empty lines. If you have an apparently empty line with
some spaces on it, this can cause odd formatting.
o Translators will mostly add wording around a L<> link, so that
L<foo(1)> becomes "the foo(1) manpage", for example (see pod2man for
details). Thus, you shouldn't write things like the L<foo> manpage,
if you want the translated document to read sensibly.
o The script pod/checkpods.PL in the Perl source distribution provides
skeletal checking for lines that look empty but aren't only, but is
there as a placeholder until someone writes Pod::Checker. The best
way to check your pod is to pass it 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.
the pod2man manpage and the section on PODs: Embedded Documentation in
the perlsyn manpage
PPPPaaaaggggeeee 5555 [ Back ]