Pod::Simple(3pm) Perl Programmers Reference Guide Pod::Simple(3pm)
NAME
Pod::Simple - framework for parsing Pod
SYNOPSIS
TODO
DESCRIPTION
Pod::Simple is a Perl library for parsing text in the Pod ("plain old
documentation") markup language that is typically used for writing
documentation for Perl and for Perl modules. The Pod format is
explained in perlpod; the most common formatter is called "perldoc".
Be sure to read "ENCODING" if your Pod contains non-ASCII characters.
Pod formatters can use Pod::Simple to parse Pod documents and render
them into plain text, HTML, or any number of other formats. Typically,
such formatters will be subclasses of Pod::Simple, and so they will
inherit its methods, like "parse_file". But note that Pod::Simple
doesn't understand and properly parse Perl itself, so if you have a
file which contains a Perl program that has a multi-line quoted string
which has lines that look like pod, Pod::Simple will treat them as pod.
This can be avoided if the file makes these into indented here
documents instead.
If you're reading this document just because you have a Pod-processing
subclass that you want to use, this document (plus the documentation
for the subclass) is probably all you need to read.
If you're reading this document because you want to write a formatter
subclass, continue reading it and then read Pod::Simple::Subclassing,
and then possibly even read perlpodspec (some of which is for parser-
writers, but much of which is notes to formatter-writers).
MAIN METHODS
"$parser = SomeClass->new();"
This returns a new parser object, where "SomeClass" is a subclass
of Pod::Simple.
"$parser->output_fh( *OUT );"
This sets the filehandle that $parser's output will be written to.
You can pass *STDOUT or *STDERR, otherwise you should probably do
something like this:
my $outfile = "output.txt";
open TXTOUT, ">$outfile" or die "Can't write to $outfile: $!";
$parser->output_fh(*TXTOUT);
...before you call one of the "$parser->parse_whatever" methods.
"$parser->output_string( \$somestring );"
This sets the string that $parser's output will be sent to, instead
of any filehandle.
"$parser->parse_file( $some_filename );"
"$parser->parse_file( *INPUT_FH );"
This reads the Pod content of the file (or filehandle) that you
specify, and processes it with that $parser object, according to
however $parser's class works, and according to whatever parser
options you have set up for this $parser object.
"$parser->parse_string_document( $all_content );"
This works just like "parse_file" except that it reads the Pod
content not from a file, but from a string that you have already in
memory.
"$parser->parse_lines( ...@lines..., undef );"
This processes the lines in @lines (where each list item must be a
defined value, and must contain exactly one line of content -- so
no items like "foo\nbar" are allowed). The final "undef" is used
to indicate the end of document being parsed.
The other "parser_whatever" methods are meant to be called only
once per $parser object; but "parse_lines" can be called as many
times per $parser object as you want, as long as the last call (and
only the last call) ends with an "undef" value.
"$parser->content_seen"
This returns true only if there has been any real content seen for
this document. Returns false in cases where the document contains
content, but does not make use of any Pod markup.
"SomeClass->filter( $filename );"
"SomeClass->filter( *INPUT_FH );"
"SomeClass->filter( \$document_content );"
This is a shortcut method for creating a new parser object, setting
the output handle to STDOUT, and then processing the specified file
(or filehandle, or in-memory document). This is handy for one-
liners like this:
perl -MPod::Simple::Text -e "Pod::Simple::Text->filter('thingy.pod')"
SECONDARY METHODS
Some of these methods might be of interest to general users, as well as
of interest to formatter-writers.
Note that the general pattern here is that the accessor-methods read
the attribute's value with "$value = $parser->attribute" and set the
attribute's value with "$parser->attribute(newvalue)". For each
accessor, I typically only mention one syntax or another, based on
which I think you are actually most likely to use.
"$parser->parse_characters( SOMEVALUE )"
The Pod parser normally expects to read octets and to convert those
octets to characters based on the "=encoding" declaration in the
Pod source. Set this option to a true value to indicate that the
Pod source is already a Perl character stream. This tells the
parser to ignore any "=encoding" command and to skip all the code
paths involving decoding octets.
"$parser->no_whining( SOMEVALUE )"
If you set this attribute to a true value, you will suppress the
parser's complaints about irregularities in the Pod coding. By
default, this attribute's value is false, meaning that
irregularities will be reported.
Note that turning this attribute to true won't suppress one or two
kinds of complaints about rarely occurring unrecoverable errors.
"$parser->no_errata_section( SOMEVALUE )"
If you set this attribute to a true value, you will stop the parser
from generating a "POD ERRORS" section at the end of the document.
By default, this attribute's value is false, meaning that an errata
section will be generated, as necessary.
"$parser->complain_stderr( SOMEVALUE )"
If you set this attribute to a true value, it will send reports of
parsing errors to STDERR. By default, this attribute's value is
false, meaning that no output is sent to STDERR.
Setting "complain_stderr" also sets "no_errata_section".
"$parser->source_filename"
This returns the filename that this parser object was set to read
from.
"$parser->doc_has_started"
This returns true if $parser has read from a source, and has seen
Pod content in it.
"$parser->source_dead"
This returns true if $parser has read from a source, and come to
the end of that source.
"$parser->strip_verbatim_indent( SOMEVALUE )"
The perlpod spec for a Verbatim paragraph is "It should be
reproduced exactly...", which means that the whitespace you've used
to indent your verbatim blocks will be preserved in the output.
This can be annoying for outputs such as HTML, where that
whitespace will remain in front of every line. It's an unfortunate
case where syntax is turned into semantics.
If the POD you're parsing adheres to a consistent indentation
policy, you can have such indentation stripped from the beginning
of every line of your verbatim blocks. This method tells
Pod::Simple what to strip. For two-space indents, you'd use:
$parser->strip_verbatim_indent(' ');
For tab indents, you'd use a tab character:
$parser->strip_verbatim_indent("\t");
If the POD is inconsistent about the indentation of verbatim
blocks, but you have figured out a heuristic to determine how much
a particular verbatim block is indented, you can pass a code
reference instead. The code reference will be executed with one
argument, an array reference of all the lines in the verbatim
block, and should return the value to be stripped from each line.
For example, if you decide that you're fine to use the first line
of the verbatim block to set the standard for indentation of the
rest of the block, you can look at the first line and return the
appropriate value, like so:
$new->strip_verbatim_indent(sub {
my $lines = shift;
(my $indent = $lines->[0]) =~ s/\S.*//;
return $indent;
});
If you'd rather treat each line individually, you can do that, too,
by just transforming them in-place in the code reference and
returning "undef". Say that you don't want any lines indented. You
can do something like this:
$new->strip_verbatim_indent(sub {
my $lines = shift;
sub { s/^\s+// for @{ $lines },
return undef;
});
"$parser->expand_verbatim_tabs( n )"
Default: 8
If after any stripping of indentation in verbatim blocks, there
remain tabs, this method call indicates what to do with them. 0
means leave them as tabs, any other number indicates that each tab
is to be translated so as to have tab stops every "n" columns.
This is independent of other methods (except that it operates after
any verbatim input stripping is done).
Like the other methods, the input parameter is not checked for
validity. "undef" or containing non-digits has the same effect as
8.
TERTIARY METHODS
"$parser->abandon_output_fh()"
Cancel output to the file handle. Any POD read by the $parser is
not effected.
"$parser->abandon_output_string()"
Cancel output to the output string. Any POD read by the $parser is
not effected.
"$parser->accept_code( @codes )"
Alias for accept_codes.
"$parser->accept_codes( @codes )"
Allows $parser to accept a list of "Formatting Codes" in perlpod.
This can be used to implement user-defined codes.
"$parser->accept_directive_as_data( @directives )"
Allows $parser to accept a list of directives for data paragraphs.
A directive is the label of a "Command Paragraph" in perlpod. A
data paragraph is one delimited by "=begin/=for/=end" directives.
This can be used to implement user-defined directives.
"$parser->accept_directive_as_processed( @directives )"
Allows $parser to accept a list of directives for processed
paragraphs. A directive is the label of a "Command Paragraph" in
perlpod. A processed paragraph is also known as "Ordinary
Paragraph" in perlpod. This can be used to implement user-defined
directives.
"$parser->accept_directive_as_verbatim( @directives )"
Allows $parser to accept a list of directives for "Verbatim
Paragraph" in perlpod. A directive is the label of a "Command
Paragraph" in perlpod. This can be used to implement user-defined
directives.
"$parser->accept_target( @targets )"
Alias for accept_targets.
"$parser->accept_target_as_text( @targets )"
Alias for accept_targets_as_text.
"$parser->accept_targets( @targets )"
Accepts targets for "=begin/=for/=end" sections of the POD.
"$parser->accept_targets_as_text( @targets )"
Accepts targets for "=begin/=for/=end" sections that should be
parsed as POD. For details, see "About Data Paragraphs" in
perlpodspec.
"$parser->any_errata_seen()"
Used to check if any errata was seen.
Example:
die "too many errors\n" if $parser->any_errata_seen();
"$parser->errata_seen()"
Returns a hash reference of all errata seen, both whines and
screams. The hash reference's keys are the line number and the
value is an array reference of the errors for that line.
Example:
if ( $parser->any_errata_seen() ) {
$logger->log( $parser->errata_seen() );
}
"$parser->detected_encoding()"
Return the encoding corresponding to "=encoding", but only if the
encoding was recognized and handled.
"$parser->encoding()"
Return encoding of the document, even if the encoding is not
correctly handled.
"$parser->parse_from_file( $source, $to )"
Parses from $source file to $to file. Similar to "parse_from_file"
in Pod::Parser.
"$parser->scream( @error_messages )"
Log an error that can't be ignored.
"$parser->unaccept_code( @codes )"
Alias for unaccept_codes.
"$parser->unaccept_codes( @codes )"
Removes @codes as valid codes for the parse.
"$parser->unaccept_directive( @directives )"
Alias for unaccept_directives.
"$parser->unaccept_directives( @directives )"
Removes @directives as valid directives for the parse.
"$parser->unaccept_target( @targets )"
Alias for unaccept_targets.
"$parser->unaccept_targets( @targets )"
Removes @targets as valid targets for the parse.
"$parser->version_report()"
Returns a string describing the version.
"$parser->whine( @error_messages )"
Log an error unless "$parser->no_whining( TRUE );".
ENCODING
The Pod::Simple parser expects to read octets. The parser will decode
the octets into Perl's internal character string representation using
the value of the "=encoding" declaration in the POD source.
If the POD source does not include an "=encoding" declaration, the
parser will attempt to guess the encoding (selecting one of UTF-8 or CP
1252) by examining the first non-ASCII bytes and applying the heuristic
described in perlpodspec. (If the POD source contains only ASCII
bytes, the encoding is assumed to be ASCII.)
If you set the "parse_characters" option to a true value the parser
will expect characters rather than octets; will ignore any "=encoding";
and will make no attempt to decode the input.
SEE ALSO
Pod::Simple::Subclassing(3)
perlpod(1)
perlpodspec(1)
Pod::Escapes(3)
perldoc(1)
SUPPORT
Questions or discussion about POD and Pod::Simple should be sent to the
pod-people@perl.org mail list. Send an empty email to
pod-people-subscribe@perl.org to subscribe.
This module is managed in an open GitHub repository,
<https://github.com/perl-pod/pod-simple/>. Feel free to fork and
contribute, or to clone <git://github.com/perl-pod/pod-simple.git> and
send patches!
Please use <https://github.com/perl-pod/pod-simple/issues/new> to file
a bug report.
COPYRIGHT AND DISCLAIMERS
Copyright (c) 2002 Sean M. Burke.
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
This program is distributed in the hope that it will be useful, but
without any warranty; without even the implied warranty of
merchantability or fitness for a particular purpose.
AUTHOR
Pod::Simple was created by Sean M. Burke <sburke@cpan.org>. But don't
bother him, he's retired.
Pod::Simple is maintained by:
o Allison Randal "allison@perl.org"
o Hans Dieter Pearcey "hdp@cpan.org"
o David E. Wheeler "dwheeler@cpan.org"
o Karl Williamson "khw@cpan.org"
Documentation has been contributed by:
o Gabor Szabo "szabgab@gmail.com"
o Shawn H Corey "SHCOREY at cpan.org"
perl v5.34.0 2020-06-14 Pod::Simple(3pm)
perl 5.34.0 - Generated Thu Mar 3 18:30:59 CST 2022