lib/perl5/5.8.8/Pod/Text/Termcap.pm

   1 # Pod::Text::Termcap -- Convert POD data to ASCII text with format escapes.
   2 # $Id: Termcap.pm,v 1.11 2003/07/09 21:52:30 eagle Exp $
   3 #
   4 # Copyright 1999, 2001, 2002 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 = 1.11;
  34
  35
  36 ##############################################################################
  37 # Overrides
  38 ##############################################################################
  39
  40 # In the initialization method, grab our terminal characteristics as well as
  41 # do all the stuff we normally do.
  42 sub initialize {
  43     my $self = shift;
  44     my ($ospeed, $term, $termios);
  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{width} = $ENV{COLUMNS} || $$term{_co} || 80;
  70         $$self{width} -= 2;
  71     }
  72
  73     $self->SUPER::initialize;
  74 }
  75
  76 # Make level one headings bold.
  77 sub cmd_head1 {
  78     my $self = shift;
  79     local $_ = shift;
  80     s/\s+$//;
  81     $self->SUPER::cmd_head1 ("$$self{BOLD}$_$$self{NORM}");
  82 }
  83
  84 # Make level two headings bold.
  85 sub cmd_head2 {
  86     my $self = shift;
  87     local $_ = shift;
  88     s/\s+$//;
  89     $self->SUPER::cmd_head2 ("$$self{BOLD}$_$$self{NORM}");
  90 }
  91
  92 # Fix up B<> and I<>.  Note that we intentionally don't do F<>.
  93 sub seq_b { my $self = shift; return "$$self{BOLD}$_[0]$$self{NORM}" }
  94 sub seq_i { my $self = shift; return "$$self{UNDL}$_[0]$$self{NORM}" }
  95
  96 # Output any included code in bold.
  97 sub output_code {
  98     my ($self, $code) = @_;
  99     $self->output ($$self{BOLD} . $code . $$self{NORM});
 100 }
 101
 102 # Override the wrapping code to igore the special sequences.
 103 sub wrap {
 104     my $self = shift;
 105     local $_ = shift;
 106     my $output = '';
 107     my $spaces = ' ' x $$self{MARGIN};
 108     my $width = $$self{width} - $$self{MARGIN};
 109     my $code = "(?:\Q$$self{BOLD}\E|\Q$$self{UNDL}\E|\Q$$self{NORM}\E)";
 110     while (length > $width) {
 111         if (s/^((?:$code?[^\n]){0,$width})\s+//
 112             || s/^((?:$code?[^\n]){$width})//) {
 113             $output .= $spaces . $1 . "\n";
 114         } else {
 115             last;
 116         }
 117     }
 118     $output .= $spaces . $_;
 119     $output =~ s/\s+$/\n\n/;
 120     $output;
 121 }
 122
 123
 124 ##############################################################################
 125 # Module return value and documentation
 126 ##############################################################################
 127
 128 1;
 129 __END__
 130
 131 =head1 NAME
 132
 133 Pod::Text::Termcap - Convert POD data to ASCII text with format escapes
 134
 135 =head1 SYNOPSIS
 136
 137     use Pod::Text::Termcap;
 138     my $parser = Pod::Text::Termcap->new (sentence => 0, width => 78);
 139
 140     # Read POD from STDIN and write to STDOUT.
 141     $parser->parse_from_filehandle;
 142
 143     # Read POD from file.pod and write to file.txt.
 144     $parser->parse_from_file ('file.pod', 'file.txt');
 145
 146 =head1 DESCRIPTION
 147
 148 Pod::Text::Termcap is a simple subclass of Pod::Text that highlights output
 149 text using the correct termcap escape sequences for the current terminal.
 150 Apart from the format codes, it in all ways functions like Pod::Text.  See
 151 L<Pod::Text> for details and available options.
 152
 153 =head1 NOTES
 154
 155 This module uses Term::Cap to retrieve the formatting escape sequences for
 156 the current terminal, and falls back on the ECMA-48 (the same in this
 157 regard as ANSI X3.64 and ISO 6429, the escape codes also used by DEC VT100
 158 terminals) if the bold, underline, and reset codes aren't set in the
 159 termcap information.
 160
 161 =head1 SEE ALSO
 162
 163 L<Pod::Text>, L<Pod::Parser>, L<Term::Cap>
 164
 165 The current version of this module is always available from its web site at
 166 L<http://www.eyrie.org/~eagle/software/podlators/>.  It is also part of the
 167 Perl core distribution as of 5.6.0.
 168
 169 =head1 AUTHOR
 170
 171 Russ Allbery <rra@stanford.edu>.
 172
 173 =head1 COPYRIGHT AND LICENSE
 174
 175 Copyright 1999, 2001, 2002 by Russ Allbery <rra@stanford.edu>.
 176
 177 This program is free software; you may redistribute it and/or modify it
 178 under the same terms as Perl itself.
 179
 180 =cut