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   1  # Pod::Text::Termcap -- Convert POD data to ASCII text with format escapes.
   2  # $Id: Termcap.pm,v 2.3 2006-01-25 23:56:54 eagle Exp $
   3  #
   4  # Copyright 1999, 2001, 2002, 2004, 2006 by Russ Allbery <rra@stanford.edu>
   5  #
   6  # This program is free software; you may redistribute it and/or modify it
   7  # under the same terms as Perl itself.
   8  #
   9  # This is a simple subclass of Pod::Text that overrides a few key methods to
  10  # output the right termcap escape sequences for formatted text on the current
  11  # terminal type.
  12  
  13  ##############################################################################
  14  # Modules and declarations
  15  ##############################################################################
  16  
  17  package Pod::Text::Termcap;
  18  
  19  require 5.004;
  20  
  21  use Pod::Text ();
  22  use POSIX ();
  23  use Term::Cap;
  24  
  25  use strict;
  26  use vars qw(@ISA $VERSION);
  27  
  28  @ISA = qw(Pod::Text);
  29  
  30  # Don't use the CVS revision as the version, since this module is also in Perl
  31  # core and too many things could munge CVS magic revision strings.  This
  32  # number should ideally be the same as the CVS revision in podlators, however.
  33  $VERSION = 2.03;
  34  
  35  ##############################################################################
  36  # Overrides
  37  ##############################################################################
  38  
  39  # In the initialization method, grab our terminal characteristics as well as
  40  # do all the stuff we normally do.
  41  sub new {
  42      my ($self, @args) = @_;
  43      my ($ospeed, $term, $termios);
  44      $self = $self->SUPER::new (@args);
  45  
  46      # $ENV{HOME} is usually not set on Windows.  The default Term::Cap path
  47      # may not work on Solaris.
  48      my $home = exists $ENV{HOME} ? "$ENV{HOME}/.termcap:" : '';
  49      $ENV{TERMPATH} = $home . '/etc/termcap:/usr/share/misc/termcap'
  50                             . ':/usr/share/lib/termcap';
  51  
  52      # Fall back on a hard-coded terminal speed if POSIX::Termios isn't
  53      # available (such as on VMS).
  54      eval { $termios = POSIX::Termios->new };
  55      if ($@) {
  56          $ospeed = 9600;
  57      } else {
  58          $termios->getattr;
  59          $ospeed = $termios->getospeed || 9600;
  60      }
  61  
  62      # Fall back on the ANSI escape sequences if Term::Cap doesn't work.
  63      eval { $term = Tgetent Term::Cap { TERM => undef, OSPEED => $ospeed } };
  64      $$self{BOLD} = $$term{_md} || "\e[1m";
  65      $$self{UNDL} = $$term{_us} || "\e[4m";
  66      $$self{NORM} = $$term{_me} || "\e[m";
  67  
  68      unless (defined $$self{width}) {
  69          $$self{opt_width} = $ENV{COLUMNS} || $$term{_co} || 80;
  70          $$self{opt_width} -= 2;
  71      }
  72  
  73      return $self;
  74  }
  75  
  76  # Make level one headings bold.
  77  sub cmd_head1 {
  78      my ($self, $attrs, $text) = @_;
  79      $text =~ s/\s+$//;
  80      $self->SUPER::cmd_head1 ($attrs, "$$self{BOLD}$text$$self{NORM}");
  81  }
  82  
  83  # Make level two headings bold.
  84  sub cmd_head2 {
  85      my ($self, $attrs, $text) = @_;
  86      $text =~ s/\s+$//;
  87      $self->SUPER::cmd_head2 ($attrs, "$$self{BOLD}$text$$self{NORM}");
  88  }
  89  
  90  # Fix up B<> and I<>.  Note that we intentionally don't do F<>.
  91  sub cmd_b { my $self = shift; return "$$self{BOLD}$_[1]$$self{NORM}" }
  92  sub cmd_i { my $self = shift; return "$$self{UNDL}$_[1]$$self{NORM}" }
  93  
  94  # Output any included code in bold.
  95  sub output_code {
  96      my ($self, $code) = @_;
  97      $self->output ($$self{BOLD} . $code . $$self{NORM});
  98  }
  99  
 100  # Override the wrapping code to igore the special sequences.
 101  sub wrap {
 102      my $self = shift;
 103      local $_ = shift;
 104      my $output = '';
 105      my $spaces = ' ' x $$self{MARGIN};
 106      my $width = $$self{opt_width} - $$self{MARGIN};
 107  
 108      # $codes matches a single special sequence.  $char matches any number of
 109      # special sequences preceeding a single character other than a newline.
 110      # We have to do $shortchar and $longchar in variables because the
 111      # construct ${char}{0,$width} didn't do the right thing until Perl 5.8.x.
 112      my $codes = "(?:\Q$$self{BOLD}\E|\Q$$self{UNDL}\E|\Q$$self{NORM}\E)";
 113      my $char = "(?:$codes*[^\\n])";
 114      my $shortchar = $char . "{0,$width}";
 115      my $longchar = $char . "{$width}";
 116      while (length > $width) {
 117          if (s/^($shortchar)\s+// || s/^($longchar)//) {
 118              $output .= $spaces . $1 . "\n";
 119          } else {
 120              last;
 121          }
 122      }
 123      $output .= $spaces . $_;
 124      $output =~ s/\s+$/\n\n/;
 125      return $output;
 126  }
 127  
 128  ##############################################################################
 129  # Module return value and documentation
 130  ##############################################################################
 131  
 132  1;
 133  __END__
 134  
 135  =head1 NAME
 136  
 137  Pod::Text::Termcap - Convert POD data to ASCII text with format escapes
 138  
 139  =head1 SYNOPSIS
 140  
 141      use Pod::Text::Termcap;
 142      my $parser = Pod::Text::Termcap->new (sentence => 0, width => 78);
 143  
 144      # Read POD from STDIN and write to STDOUT.
 145      $parser->parse_from_filehandle;
 146  
 147      # Read POD from file.pod and write to file.txt.
 148      $parser->parse_from_file ('file.pod', 'file.txt');
 149  
 150  =head1 DESCRIPTION
 151  
 152  Pod::Text::Termcap is a simple subclass of Pod::Text that highlights output
 153  text using the correct termcap escape sequences for the current terminal.
 154  Apart from the format codes, it in all ways functions like Pod::Text.  See
 155  L<Pod::Text> for details and available options.
 156  
 157  =head1 NOTES
 158  
 159  This module uses Term::Cap to retrieve the formatting escape sequences for
 160  the current terminal, and falls back on the ECMA-48 (the same in this
 161  regard as ANSI X3.64 and ISO 6429, the escape codes also used by DEC VT100
 162  terminals) if the bold, underline, and reset codes aren't set in the
 163  termcap information.
 164  
 165  =head1 SEE ALSO
 166  
 167  L<Pod::Text>, L<Pod::Simple>, L<Term::Cap>
 168  
 169  The current version of this module is always available from its web site at
 170  L<http://www.eyrie.org/~eagle/software/podlators/>.  It is also part of the
 171  Perl core distribution as of 5.6.0.
 172  
 173  =head1 AUTHOR
 174  
 175  Russ Allbery <rra@stanford.edu>.
 176  
 177  =head1 COPYRIGHT AND LICENSE
 178  
 179  Copyright 1999, 2001, 2002, 2004, 2006 by Russ Allbery <rra@stanford.edu>.
 180  
 181  This program is free software; you may redistribute it and/or modify it
 182  under the same terms as Perl itself.
 183  
 184  =cut