1Pod::Simple(3pm) Perl Programmers Reference Guide Pod::Simple(3pm)
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6 Pod::Simple - framework for parsing Pod
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9 TODO
10
12 Pod::Simple is a Perl library for parsing text in the Pod ("plain old
13 documentation") markup language that is typically used for writing
14 documentation for Perl and for Perl modules. The Pod format is
15 explained perlpod; the most common formatter is called "perldoc".
16 Pod formatters can use Pod::Simple to parse Pod documents and render
18 them into plain text, HTML, or any number of other formats. Typically,
19 such formatters will be subclasses of Pod::Simple, and so they will
20 inherit its methods, like "parse_file".
21 If you're reading this document just because you have a Pod-processing
23 subclass that you want to use, this document (plus the documentation
24 for the subclass) is probably all you need to read.
25 If you're reading this document because you want to write a formatter
27 subclass, continue reading it and then read Pod::Simple::Subclassing,
28 and then possibly even read perlpodspec (some of which is for parser-
29 writers, but much of which is notes to formatter-writers).
30
32 "$parser = SomeClass->new();"
33 This returns a new parser object, where "SomeClass" is a subclass
34 of Pod::Simple.
35 "$parser->output_fh( *OUT );"
37 This sets the filehandle that $parser's output will be written to.
38 You can pass *STDOUT, otherwise you should probably do something
39 like this:
40 my $outfile = "output.txt";
42 open TXTOUT, ">$outfile" or die "Can't write to $outfile: $!";
43 $parser->output_fh(*TXTOUT);
44 ...before you call one of the "$parser->parse_whatever" methods.
46 "$parser->output_string( \$somestring );"
48 This sets the string that $parser's output will be sent to, instead
49 of any filehandle.
50 "$parser->parse_file( $some_filename );"
52 "$parser->parse_file( *INPUT_FH );"
53 This reads the Pod content of the file (or filehandle) that you
54 specify, and processes it with that $parser object, according to
55 however $parser's class works, and according to whatever parser
56 options you have set up for this $parser object.
57 "$parser->parse_string_document( $all_content );"
59 This works just like "parse_file" except that it reads the Pod
60 content not from a file, but from a string that you have already in
61 memory.
62 "$parser->parse_lines( ...@lines..., undef );"
64 This processes the lines in @lines (where each list item must be a
65 defined value, and must contain exactly one line of content -- so
66 no items like "foo\nbar" are allowed). The final "undef" is used
67 to indicate the end of document being parsed.
68 The other "parser_whatever" methods are meant to be called only
70 once per $parser object; but "parse_lines" can be called as many
71 times per $parser object as you want, as long as the last call (and
72 only the last call) ends with an "undef" value.
73 "$parser->content_seen"
75 This returns true only if there has been any real content seen for
76 this document.
77 "SomeClass->filter( $filename );"
79 "SomeClass->filter( *INPUT_FH );"
80 "SomeClass->filter( \$document_content );"
81 This is a shortcut method for creating a new parser object, setting
82 the output handle to STDOUT, and then processing the specified file
83 (or filehandle, or in-memory document). This is handy for one-
84 liners like this:
85 perl -MPod::Simple::Text -e "Pod::Simple::Text->filter('thingy.pod')"
87
89 Some of these methods might be of interest to general users, as well as
90 of interest to formatter-writers.
91 Note that the general pattern here is that the accessor-methods read
93 the attribute's value with "$value = $parser->attribute" and set the
94 attribute's value with "$parser->attribute(newvalue)". For each
95 accessor, I typically only mention one syntax or another, based on
96 which I think you are actually most likely to use.
97 "$parser->no_whining( SOMEVALUE )"
99 If you set this attribute to a true value, you will suppress the
100 parser's complaints about irregularities in the Pod coding. By
101 default, this attribute's value is false, meaning that
102 irregularities will be reported.
103 Note that turning this attribute to true won't suppress one or two
105 kinds of complaints about rarely occurring unrecoverable errors.
106 "$parser->no_errata_section( SOMEVALUE )"
108 If you set this attribute to a true value, you will stop the parser
109 from generating a "POD ERRORS" section at the end of the document.
110 By default, this attribute's value is false, meaning that an errata
111 section will be generated, as necessary.
112 "$parser->complain_stderr( SOMEVALUE )"
114 If you set this attribute to a true value, it will send reports of
115 parsing errors to STDERR. By default, this attribute's value is
116 false, meaning that no output is sent to STDERR.
117 Setting "complain_stderr" also sets "no_errata_section".
119 "$parser->source_filename"
121 This returns the filename that this parser object was set to read
122 from.
123 "$parser->doc_has_started"
125 This returns true if $parser has read from a source, and has seen
126 Pod content in it.
127 "$parser->source_dead"
129 This returns true if $parser has read from a source, and come to
130 the end of that source.
131 "$parser->strip_verbatim_indent( SOMEVALUE )"
133 The perlpod spec for a Verbatim paragraph is "It should be
134 reproduced exactly...", which means that the whitespace you've used
135 to indent your verbatim blocks will be preserved in the output.
136 This can be annoying for outputs such as HTML, where that
137 whitespace will remain in front of every line. It's an unfortunate
138 case where syntax is turned into semantics.
139 If the POD your parsing adheres to a consistent indentation policy,
141 you can have such indentation stripped from the beginning of every
142 line of your verbatim blocks. This method tells Pod::Simple what to
143 strip. For two-space indents, you'd use:
144 $parser->strip_verbatim_indent(' ');
146 For tab indents, you'd use a tab character:
148 $parser->strip_verbatim_indent("\t");
150 If the POD is inconsistent about the indentation of verbatim
152 blocks, but you have figured out a heuristic to determine how much
153 a particular verbatim block is indented, you can pass a code
154 reference instead. The code reference will be executed with one
155 argument, an array reference of all the lines in the verbatim
156 block, and should return the value to be stripped from each line.
157 For example, if you decide that you're fine to use the first line
158 of the verbatim block to set the standard for indentation of the
159 rest of the block, you can look at the first line and return the
160 appropriate value, like so:
161 $new->strip_verbatim_indent(sub {
163 my $lines = shift;
164 (my $indent = $lines->[0]) =~ s/\S.*//;
165 return $indent;
166 });
167 If you'd rather treat each line individually, you can do that, too,
169 by just transforming them in-place in the code reference and
170 returning "undef". Say that you don't want any lines indented. You
171 can do something like this:
172 $new->strip_verbatim_indent(sub {
174 my $lines = shift;
175 sub { s/^\s+// for @{ $lines },
176 return undef;
177 });
178
180 This is just a beta release -- there are a good number of things still
181 left to do. Notably, support for EBCDIC platforms is still half-done,
182 an untested.
183
185 Pod::Simple::Subclassing
186 perlpod
188 perlpodspec
190 Pod::Escapes
192 perldoc
194
196 Questions or discussion about POD and Pod::Simple should be sent to the
197 pod-people@perl.org mail list. Send an empty email to
198 pod-people-subscribe@perl.org to subscribe.
199 This module is managed in an open GitHub repository,
201 http://github.com/theory/pod-simple/ <http://github.com/theory/pod-
202 simple/>. Feel free to fork and contribute, or to clone
203 git://github.com/theory/pod-simple.git <git://github.com/theory/pod-
204 simple.git> and send patches!
205 Patches against Pod::Simple are welcome. Please send bug reports to
207 <bug-pod-simple@rt.cpan.org>.
208
210 Copyright (c) 2002 Sean M. Burke.
211 This library is free software; you can redistribute it and/or modify it
213 under the same terms as Perl itself.
214 This program is distributed in the hope that it will be useful, but
216 without any warranty; without even the implied warranty of
217 merchantability or fitness for a particular purpose.
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220 Pod::Simple was created by Sean M. Burke <sburke@cpan.org>. But don't
221 bother him, he's retired.
222 Pod::Simple is maintained by:
224 · Allison Randal "allison@perl.org"
226 · Hans Dieter Pearcey "hdp@cpan.org"
228 · David E. Wheeler "dwheeler@cpan.org"
230perl v5.12.4 2011-06-01 Pod::Simple(3pm)