User Contributed Perl Documentation PERLPOD(1) NNNNAAAAMMMMEEEE perlpod - plain old documentation DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN 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 paragraphs: verbatim, command, and ordinary text. VVVVeeeerrrrbbbbaaaattttiiiimmmm PPPPaaaarrrraaaaggggrrrraaaapppphhhh 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. CCCCoooommmmmmmmaaaannnndddd PPPPaaaarrrraaaaggggrrrraaaapppphhhh 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 =head1 heading =head2 heading =item text =over N =back =cut =pod =for X =begin X =end X =pod =cut 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 =head2 Head1 and head2 produce first and second level headings, with the text in the same paragraph as the "=headn" directive forming the heading description. 23/Jun/1999 Last change: perl 5.005, patch 03 1 User Contributed Perl Documentation PERLPOD(1) =over =back =item 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 =end 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

This is a raw HTML paragraph

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 particular format. Here are some examples of how to use these: =begin html
Figure 1.
23/Jun/1999 Last change: perl 5.005, patch 03 2 User Contributed Perl Documentation PERLPOD(1) =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.) And don't forget, when using any command, that the command lasts up until the end of the ppppaaaarrrraaaaggggrrrraaaapppphhhh, not the line. Hence in the examples below, you can see the empty lines after each command to end its paragraph. Some examples of lists include: =over 4 =item * First item =item * Second item =back =over 4 =item Foo() Description of Foo function =item Bar() Description of Bar function =back 23/Jun/1999 Last change: perl 5.005, patch 03 3 User Contributed Perl Documentation PERLPOD(1) OOOOrrrrddddiiiinnnnaaaarrrryyyy BBBBlllloooocccckkkk ooooffff TTTTeeeexxxxtttt It will be filled, and maybe even justified. Certain interior sequences are recognized both here and in commands: I italicize text, used for emphasis or variables B embolden text, used for switches and programs S text contains non-breaking spaces C literal code L A link (cross reference) to name L manual page L item in manual page L section in other manual page L<"sec"> section in this manual page (the quotes are optional) L ditto same as above but only 'text' is used for output. (Text can not contain the characters '/' and '|', and should contain matched '<' or '>') L L L L L F Used for filenames X An index entry Z<> A zero-width character E A named character (very similar to HTML escapes) E A literal < E A literal > E A literal / E A literal | (these are optional except in other interior sequences and when preceded by a capital letter) E Character number n (probably in ASCII) E Some non-numeric HTML entity, such as E TTTThhhheeee IIIInnnntttteeeennnntttt 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 vvvviiii). 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. 23/Jun/1999 Last change: perl 5.005, patch 03 4 User Contributed Perl Documentation PERLPOD(1) In particular, you can leave things like this verbatim in your text: Perl FILEHANDLE $variable function() manpage(3r) 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 ppppoooodddd2222mmmmaaaannnn (that's for _n_r_o_f_f(1) and _t_r_o_f_f(1)), ppppoooodddd2222tttteeeexxxxtttt, ppppoooodddd2222hhhhttttmmmmllll, ppppoooodddd2222llllaaaatttteeeexxxx, and ppppoooodddd2222ffffmmmm. EEEEmmmmbbbbeeeeddddddddiiiinnnngggg PPPPooooddddssss iiiinnnn PPPPeeeerrrrllll MMMMoooodddduuuulllleeeessss 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. __END__ =head1 NAME modern - I am a modern module If you had not had that empty line there, then the translators wouldn't have seen it. CCCCoooommmmmmmmoooonnnn PPPPoooodddd PPPPiiiittttffffaaaallllllllssss +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 becomes "the _f_o_o(1) manpage", for example (see ppppoooodddd2222mmmmaaaannnn for details). Thus, you shouldn't write things like the L manpage, if you want the translated document to read sensibly. 23/Jun/1999 Last change: perl 5.005, patch 03 5 User Contributed Perl Documentation PERLPOD(1) If you don need or want total control of the text used for a link in the output use the form L instead. +o The script _p_o_d/_c_h_e_c_k_p_o_d_s._P_L in the Perl source distribution provides skeletal checking for lines that look empty but aren't oooonnnnllllyyyy, 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. SSSSEEEEEEEE AAAALLLLSSSSOOOO the _p_o_d_2_m_a_n manpage and the section on _P_O_D_s: _E_m_b_e_d_d_e_d _D_o_c_u_m_e_n_t_a_t_i_o_n in the _p_e_r_l_s_y_n manpage AAAAUUUUTTTTHHHHOOOORRRR Larry Wall 23/Jun/1999 Last change: perl 5.005, patch 03 6