pod2markdown

#!/usr/local/bin/perl
use 5.008;
use strict;
use warnings;
# PODNAME: pod2markdown
# ABSTRACT: Convert POD text to Markdown

use Pod::Markdown;
use Getopt::Long;
use Pod::Usage;

my %opts = (
  # Since we're writing to a file the module needs to know that it has to do
  # some kind of encoding.  Default to UTF-8.
  output_encoding => 'UTF-8',
);

GetOptions(\%opts, qw(
  help|h
  html_encode_chars|html-encode-chars=s
  match_encoding|match-encoding|m
  man_url_prefix|man-url-prefix=s
  output_encoding|output-encoding|e=s
  utf8|utf-8|u
)) or pod2usage(2);
pod2usage(1) if $opts{help};

# TODO: Test PERL_UNICODE and/or layers on the handle?

# Expand alias (-u is an alias for -e UTF-8).
$opts{output_encoding} = 'UTF-8' if delete $opts{utf8};

# TODO: Pod::Simple::parse_from_file(@ARGV[0,1]);

my $in_fh  = get_handle(shift(@ARGV), '<', \*STDIN);
my $out_fh = get_handle(shift(@ARGV), '>', \*STDOUT);

# Undo any PERL_UNICODE effects.
# Pod::Simple expects to receive bytes, and we're going to return bytes.
binmode($_, ':bytes') for ($in_fh, $out_fh);

convert($in_fh, $out_fh);

sub convert {
    my ($in_file, $out_file) = @_;
    my $parser = Pod::Markdown->new(%opts);
    $parser->output_fh($out_file);
    $parser->parse_file($in_file);
}

sub get_handle {
  my ($path, $op, $default) = @_;
  (!defined($path) || $path eq '-') ? $default : do {
    open(my $fh, $op, $path)
      or die "Failed to open '$path': $!\n";
    $fh;
  };
}

=head1 SYNOPSIS

    # parse STDIN, print to STDOUT
    $ pod2markdown < POD_File > Markdown_File

    # parse file, print to STDOUT
    $ pod2markdown input.pod

    # parse file, print to file
    $ pod2markdown input.pod output.mkdn

    # parse STDIN, print to file
    $ pod2markdown - output.mkdn

=head1 DESCRIPTION

This program uses L<Pod::Markdown> to convert POD into Markdown sources.

UTF-8 is the default output encoding
if no encoding options are specified (see L</OPTIONS>).

It accepts two optional arguments:

=for :list
* input pod file (defaults to C<STDIN>)
* output markdown file (defaults to C<STDOUT>)

=head1 OPTIONS

=over

=for stopwords
html

=item --html-encode-chars

A list of characters to encode as HTML entities.
Pass a regexp character class, or C<1> to mean control chars, high-bit chars, and C<< <&>"' >>.

See L<Pod::Markdown/html_encode_chars> for more information.

=item --match-encoding (-m)

Use the same C<< =encoding >> as the input pod for the output file.

=item --man-url-prefix

Alters the man page urls that are created from C<< LE<lt>E<gt> >> codes.

The default is C<http://man.he.net/man>.

See L<Pod::Markdown/man_url_prefix> for more information.

=item --output-encoding (-e)

Specify the encoding for the output file.

=item --utf8 (-u)

Alias for C<< -e UTF-8 >>.

=back

=head1 SEE ALSO

This program is strongly based on C<pod2mdwn> from L<Module::Build::IkiWiki>.