Pod Translators and Modules (Programming Perl)

26.2. Pod Translators and Modules

Perl is bundled with several pod translators that convert pod documents (or the embedded pod in other types of documents) into various formats. All should be 8-bit clean.

pod2text

Converts pod into text. Normally, this text will be 7-bit ASCII, but it will be 8-bit if it had 8-bit input, or specifically ISO-8859-1 (or Unicode) if you use sequences like LE<uacute>thien for Lúthien or EE<auml>rendil for Eärendil.

If you have a file with pod in it, the easiest (although perhaps not the prettiest) way to view just the formatted pod would be:

% pod2text File.pm | more

Then again, pod is supposed to be human readable without formatting.

pod2man

Converts pod into Unix manpage format suitable for viewing through nroff(1) or creating typeset copies via troff(1). For example:

% pod2man File.pm | nroff -man | more

% pod2man File.pm | troff -man -Tps -t > tmppage.ps
% ghostview tmppage.ps

and to print:

% lpr -Ppostscript tmppage.ps

pod2html

Converts pod into HTML for use with your favorite viewer:

% pod2html File.pm > tmppage.html
% lynx tmppage.html
% netscape -remote "openURL(file:`pwd`/tmppage.html)"

That last one is a netscape hack that works if you already have netscape running somewhere to tell that incarnation to load the page. Otherwise, just call it as you did lynx.

pod2latex

Converts pod into [LaTeX].

Additional translators are available on CPAN for other formats.

Translators exhibit different default behaviors depending on the output format. For instance, if your pod has a prose paragraph saying:

This is a $variable right here

then pod2html will turn that into:

This is a <STRONG>$variable</STRONG> right here

but pod2text will leave it unadorned, since the dollar should be enough to let it be read.

You should write your pod as close to plain text as you possibly can, with as few explicit markups as you can get away with. It is up to the individual translator to decide how things in your text should be represented. That means letting the translator figure out how to create paired quotes, how to fill and adjust text, how to find a smaller font for words in all capitals, etc. Since these were written to process Perl documentation, most translators[1] should also recognize unadorned items like these and render them appropriately:

[1]If you're designing a general-purpose pod translator, not one for Perl code, your criteria may vary.

FILEHANDLE
$scalar
@array
function()
manpage(3r)
somebody@someplace.com
http://foo.com/

Perl also comes with several standard modules for parsing and converting pod, including Pod::Checker (and the associated podchecker utility) for checking the syntax of pod documents, Pod::Find for finding pod documents in directory trees, and Pod::Parser for creating your own pod utilities.

Note that pod translators should only look at paragraphs beginning with a pod directive (this makes parsing easier), whereas the compiler actually knows to look for pod escapes even in the middle of a paragraph. This means that the following secret stuff will be ignored by both the compiler and the translators.

$a=3;
=secret stuff
warn "Neither POD nor CODE!?"
=cut back
print "got $a\n";

You probably shouldn't rely upon the warn being podded out forever. Not all pod translators are well-behaved in this regard, and the compiler may someday become pickier.