3 perlpod - plain old documentation
7 A pod-to-whatever translator reads a pod file paragraph by paragraph,
8 and translates it to the appropriate output format. There are
9 three kinds of paragraphs:
15 A verbatim paragraph, distinguished by being indented (that is,
16 it starts with space or tab). It should be reproduced exactly,
17 with tabs assumed to be on 8-column boundaries. There are no
18 special formatting escapes, so you can't italicize or anything
19 like that. A \ means \, and nothing else.
23 A command. All command paragraphs start with "=", followed by an
24 identifier, followed by arbitrary text that the command can
25 use however it pleases. Currently recognized commands are
35 The "=pod" directive does nothing beyond telling the compiler to lay
36 off of through the next "=cut". It's useful for adding another
37 paragraph to the doc if you're mixing up code and pod a lot.
39 Head1 and head2 produce first and second level headings, with the text on
40 the same paragraph as "=headn" forming the heading description.
42 Item, over, and back require a little more explanation: Over starts a
43 section specifically for the generation of a list using =item commands. At
44 the end of your list, use =back to end it. You will probably want to give
45 "4" as the number to =over, as some formatters will use this for indentation.
46 This should probably be a default. Note also that there are some basic rules
47 to using =item: don't use them outside of an =over/=back block, use at least
48 one inside an =over/=back block, you don't _have_ to include the =back if
49 the list just runs off the document, and perhaps most importantly, keep the
50 items consistent: either use "=item *" for all of them, to produce bullets,
51 or use "=item 1.", "=item 2.", etc., to produce numbered lists, or use
52 "=item foo", "=item bar", etc., i.e., things that looks nothing like bullets
53 or numbers. If you start with bullets or numbers, stick with them, as many
54 formatters use the first =item type to decide how to format the list.
56 And don't forget, when using any command, that that command lasts up until
57 the end of the B<paragraph>, not the line. Hence in the examples below, you
58 can see the blank lines after each command to end its paragraph.
60 Some examples of lists include:
78 Description of Foo function
82 Description of Bar function
88 An ordinary block of text. It will be filled, and maybe even
89 justified. Certain interior sequences are recognized both
92 I<text> italicize text, used for emphasis or variables
93 B<text> embolden text, used for switches and programs
94 S<text> text contains non-breaking spaces
96 L<name> A link (cross reference) to name
98 L<name/ident> item in manual page
99 L<name/"sec"> section in other manual page
100 L<"sec"> section in this manual page
101 (the quotes are optional)
103 F<file> Used for filenames
104 X<index> An index entry
105 Z<> A zero-width character
106 E<escape> An HTML escape
109 (these are optional except in other interior
110 sequences and when preceded by a capital letter)
111 E<n> Character number n
112 E<html> Some non-numeric HTML entity, such
117 That's it. The intent is simplicity, not power. I wanted paragraphs
118 to look like paragraphs (block format), so that they stand out
119 visually, and so that I could run them through fmt easily to reformat
120 them (that's F7 in my version of B<vi>). I wanted the translator (and not
121 me) to worry about whether " or ' is a left quote or a right quote
122 within filled text, and I wanted it to leave the quotes alone, dammit, in
123 verbatim mode, so I could slurp in a working program, shift it over 4
124 spaces, and have it print out, er, verbatim. And presumably in a
127 In particular, you can leave things like this verbatim in your text:
135 Doubtless a few other commands or sequences will need to be added along
136 the way, but I've gotten along surprisingly well with just these.
138 Note that I'm not at all claiming this to be sufficient for producing a
139 book. I'm just trying to make an idiot-proof common source for nroff,
140 TeX, and other markup languages, as used for online documentation.
141 Translators exist for B<pod2man> (that's for nroff(1) and troff(1)),
142 B<pod2html>, B<pod2latex>, and B<pod2fm>.
144 =head1 Embedding Pods in Perl Modules
146 You can embed pod documentation in your Perl scripts. Start your
147 documentation with a =head1 command at the beg, and end it with
148 an =cut command. Perl will ignore the pod text. See any of the
149 supplied library modules for examples. If you're going to put
150 your pods at the end of the file, and you're using an __END__
151 or __DATA__ cut mark, make sure to put a blank line there before
152 the first pod directive.
158 modern - I am a modern module
160 If you had not had that blank line there, then the translators wouldn't
163 =head1 Common Pod Pitfalls
169 Pod translators usually will require paragraphs to be separated by
170 completely empty lines. If you have an apparently blank line with
171 some spaces on it, this can cause odd formatting.
175 Translators will mostly add wording around a LE<lt>E<gt> link, so that
176 C<LE<lt>foo(1)E<gt>> becomes "the I<foo>(1) manpage", for example (see
177 B<pod2man> for details). Thus, you shouldn't write things like C<the
178 LE<lt>fooE<gt> manpage>, if you want the translated document to read
183 The script F<pod/checkpods.PL> in the Perl source distribution
184 provides skeletal checking for lines that look blank but aren't
185 B<only>, but is there as a placeholder until someone writes
186 Pod::Checker. The best way to check your pod is to pass it through
187 one or more translators and proofread the result, or print out the
188 result and proofread that. Some of the problems found may be bugs in
189 the translators, which you may or may not wish to work around.
195 L<pod2man> and L<perlsyn/"PODs: Embedded Documentation">