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
38 The "=pod" directive does nothing beyond telling the compiler to lay
39 off of through the next "=cut". It's useful for adding another
40 paragraph to the doc if you're mixing up code and pod a lot.
42 Head1 and head2 produce first and second level headings, with the text on
43 the same paragraph as "=headn" forming the heading description.
45 Item, over, and back require a little more explanation: Over starts a
46 section specifically for the generation of a list using =item commands. At
47 the end of your list, use =back to end it. You will probably want to give
48 "4" as the number to =over, as some formatters will use this for indentation.
49 This should probably be a default. Note also that there are some basic rules
50 to using =item: don't use them outside of an =over/=back block, use at least
51 one inside an =over/=back block, you don't _have_ to include the =back if
52 the list just runs off the document, and perhaps most importantly, keep the
53 items consistent: either use "=item *" for all of them, to produce bullets,
54 or use "=item 1.", "=item 2.", etc., to produce numbered lists, or use
55 "=item foo", "=item bar", etc., i.e., things that looks nothing like bullets
56 or numbers. If you start with bullets or numbers, stick with them, as many
57 formatters use the first =item type to decide how to format the list.
59 For and begin/end let you include sections that are not interpreted as pod
60 text, but in a format that a particular formatter is looking for. A
61 formatter that can utilize that format will use the section, otherwise it
62 will be completely ignored. "=for" specifies that the entire paragraph
63 should is in the format indicated by the first word after "=for", like this:
66 <p> This is a raw HTML paragraph </p>
68 The paired commands "=begin" and "=end" work very similarly to =for, but
69 instead of only accepting a single paragraph, all text from =begin to a
70 paragraph with a matching =end are treated as a particular format.
72 Here are some examples of how to use these:
76 <br>Figure 1.<IMG SRC="figure1.png"><br>
91 Some format names that formatters currently are known to accept include
92 "roff", "man", "latex", "tex", "text", and "html". (Some formatters will
93 treat some of these as synonyms.)
95 And don't forget, when using any command, that that command lasts up until
96 the end of the B<paragraph>, not the line. Hence in the examples below, you
97 can see the blank lines after each command to end its paragraph.
99 Some examples of lists include:
117 Description of Foo function
121 Description of Bar function
127 An ordinary block of text. It will be filled, and maybe even
128 justified. Certain interior sequences are recognized both
129 here and in commands:
131 I<text> italicize text, used for emphasis or variables
132 B<text> embolden text, used for switches and programs
133 S<text> text contains non-breaking spaces
135 L<name> A link (cross reference) to name
137 L<name/ident> item in manual page
138 L<name/"sec"> section in other manual page
139 L<"sec"> section in this manual page
140 (the quotes are optional)
142 F<file> Used for filenames
143 X<index> An index entry
144 Z<> A zero-width character
145 E<escape> A named character (very similar to HTML escapes)
148 (these are optional except in other interior
149 sequences and when preceded by a capital letter)
150 E<n> Character number n (probably in ASCII)
151 E<html> Some non-numeric HTML entity, such
156 That's it. The intent is simplicity, not power. I wanted paragraphs
157 to look like paragraphs (block format), so that they stand out
158 visually, and so that I could run them through fmt easily to reformat
159 them (that's F7 in my version of B<vi>). I wanted the translator (and not
160 me) to worry about whether " or ' is a left quote or a right quote
161 within filled text, and I wanted it to leave the quotes alone, dammit, in
162 verbatim mode, so I could slurp in a working program, shift it over 4
163 spaces, and have it print out, er, verbatim. And presumably in a
166 In particular, you can leave things like this verbatim in your text:
174 Doubtless a few other commands or sequences will need to be added along
175 the way, but I've gotten along surprisingly well with just these.
177 Note that I'm not at all claiming this to be sufficient for producing a
178 book. I'm just trying to make an idiot-proof common source for nroff,
179 TeX, and other markup languages, as used for online documentation.
180 Translators exist for B<pod2man> (that's for nroff(1) and troff(1)),
181 B<pod2html>, B<pod2latex>, and B<pod2fm>.
183 =head1 Embedding Pods in Perl Modules
185 You can embed pod documentation in your Perl scripts. Start your
186 documentation with a =head1 command at the beg, and end it with
187 an =cut command. Perl will ignore the pod text. See any of the
188 supplied library modules for examples. If you're going to put
189 your pods at the end of the file, and you're using an __END__
190 or __DATA__ cut mark, make sure to put a blank line there before
191 the first pod directive.
197 modern - I am a modern module
199 If you had not had that blank line there, then the translators wouldn't
202 =head1 Common Pod Pitfalls
208 Pod translators usually will require paragraphs to be separated by
209 completely empty lines. If you have an apparently blank line with
210 some spaces on it, this can cause odd formatting.
214 Translators will mostly add wording around a LE<lt>E<gt> link, so that
215 C<LE<lt>foo(1)E<gt>> becomes "the I<foo>(1) manpage", for example (see
216 B<pod2man> for details). Thus, you shouldn't write things like C<the
217 LE<lt>fooE<gt> manpage>, if you want the translated document to read
222 The script F<pod/checkpods.PL> in the Perl source distribution
223 provides skeletal checking for lines that look blank but aren't
224 B<only>, but is there as a placeholder until someone writes
225 Pod::Checker. The best way to check your pod is to pass it through
226 one or more translators and proofread the result, or print out the
227 result and proofread that. Some of the problems found may be bugs in
228 the translators, which you may or may not wish to work around.
234 L<pod2man> and L<perlsyn/"PODs: Embedded Documentation">