Pod::Simple(3p) Perl Programmers Reference Guide Pod::Simple(3p) #

Pod::Simple(3p) Perl Programmers Reference Guide Pod::Simple(3p)

NNAAMMEE #

 Pod::Simple - framework for parsing Pod

SSYYNNOOPPSSIISS #

TODO #

DDEESSCCRRIIPPTTIIOONN #

 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).

MMAAIINN MMEETTHHOODDSS #

 "$parser = _S_o_m_e_C_l_a_s_s->new();"
     This returns a new parser object, where _"_S_o_m_e_C_l_a_s_s_" 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__w_h_a_t_e_v_e_r" methods.

 "$parser->output_string( \$somestring );"
     This sets the string that $parser's output will be sent to, instead
     of any filehandle.

 "$parser->parse_file( _$_s_o_m_e___f_i_l_e_n_a_m_e );"
 "$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.

 "$parser->parse_string_document( _$_a_l_l___c_o_n_t_e_n_t );"
     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( _._._._@_l_i_n_e_s_._._., 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__w_h_a_t_e_v_e_r" 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.

 "_S_o_m_e_C_l_a_s_s->filter( _$_f_i_l_e_n_a_m_e );"
 "_S_o_m_e_C_l_a_s_s->filter( _*_I_N_P_U_T___F_H );"
 "_S_o_m_e_C_l_a_s_s->filter( _\_$_d_o_c_u_m_e_n_t___c_o_n_t_e_n_t );"
     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')"

SSEECCOONNDDAARRYY MMEETTHHOODDSS #

 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 = $parser->_a_t_t_r_i_b_u_t_e" and set the
 attribute's value with "$parser->_a_t_t_r_i_b_u_t_e(_n_e_w_v_a_l_u_e)".  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( _S_O_M_E_V_A_L_U_E )"
     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( _S_O_M_E_V_A_L_U_E )"
     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( _S_O_M_E_V_A_L_U_E )"
     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( _S_O_M_E_V_A_L_U_E )"
     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( _S_O_M_E_V_A_L_U_E )"
     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 _a_n_y 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.

TTEERRTTIIAARRYY MMEETTHHOODDSS #

 "$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.

     _E_x_a_m_p_l_e_:

       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.

     _E_x_a_m_p_l_e_:

       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 );".

EENNCCOODDIINNGG #

 The Pod::Simple parser expects to read oocctteettss.  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.

SSEEEE AALLSSOO #

 Pod::Simple::Subclassing

 perlpod

 perlpodspec

 Pod::Escapes

 perldoc

SSUUPPPPOORRTT #

 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.

CCOOPPYYRRIIGGHHTT AANNDD DDIISSCCLLAAIIMMEERRSS #

 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.

AAUUTTHHOORR #

 Pod::Simple was created by Sean M. Burke <sburke@cpan.org>.  But don't
 bother him, he's retired.

 Pod::Simple is maintained by:

 •   Allison Randal "allison@perl.org"

 •   Hans Dieter Pearcey "hdp@cpan.org"

 •   David E. Wheeler "dwheeler@cpan.org"

 •   Karl Williamson "khw@cpan.org"

 Documentation has been contributed by:

 •   Gabor Szabo "szabgab@gmail.com"

 •   Shawn H Corey  "SHCOREY at cpan.org"

perl v5.36.3 2021-03-02 Pod::Simple(3p)