NAME
    String::Diff - Simple diff to String

SYNOPSIS
      use String::Diff;
      use String::Diff qw( diff_fully diff diff_merge diff_regexp );# export functions

      # simple diff
      my($old, $new) = String::Diff::diff('this is Perl', 'this is Ruby');
      print "$old\n";# this is [Perl]
      print "$new\n";# this is {Ruby}

      my $diff = String::Diff::diff('this is Perl', 'this is Ruby');
      print "$diff->[0]\n";# this is [Perl]
      print "$diff->[1]\n";# this is {Ruby}

      my $diff = String::Diff::diff('this is Perl', 'this is Ruby',
          remove_open => '<del>',
          remove_close => '</del>',
          append_open => '<ins>',
          append_close => '</ins>',
      );
      print "$diff->[0]\n";# this is <del>Perl</del>
      print "$diff->[1]\n";# this is <ins>Ruby</ins>

      # merged
      my $diff = String::Diff::diff_merge('this is Perl', 'this is Ruby');
      print "$diff\n";# this is [Perl]{Ruby}

      my $diff = String::Diff::diff_merge('this is Perl', 'this is Ruby',
          remove_open => '<del>',
          remove_close => '</del>',
          append_open => '<ins>',
          append_close => '</ins>',
      );
      print "$diff\n";# this is <del>Perl</del><ins>Ruby</ins>

      # change to default marks
      %String::Diff::DEFAULT_MARKS = (
          remove_open  => '<del>',
          remove_close => '</del>',
          append_open  => '<ins>',
          append_close => '</ins>',
          separator    => '&lt;-OLD|NEW-&gt;', # for diff_merge
      );

      # generated for regexp
      my $diff = String::Diff::diff_regexp('this is Perl', 'this is Ruby');
      print "$diff\n";# this\ is\ (?:Perl|Ruby)

      # detailed list
      my $diff = String::Diff::diff_fully('this is Perl', 'this is Ruby');
      for my $line (@{ $diff->[0] }) {
          print "$line->[0]: '$line->[1]'\n";
      }
      # u: 'this is '
      # -: 'Perl'

      for my $line (@{ $diff->[1] }) {
          print "$line->[0]: '$line->[1]'\n";
      }
      # u: 'this is '
      # +: 'Ruby'

DESCRIPTION
    String::Diff is the difference of a consecutive string is made. after
    general diff is done, the difference in the line is searchable.

    the mark of the addition and the deletion can be freely changed. the
    color is colored to the terminal with ANSI, using the HTML display it.

    after the line is divided, diff is taken when 'linebreak' option is
    specified.

      my($old_string, $new_string) = String::Diff::diff_fully('this is Perl', 'this is Ruby', linebreak => 1);
      my($old_string, $new_string) = String::Diff::diff('this is Perl', 'this is Ruby', linebreak => 1);
      my $string = String::Diff::diff_merge('this is Perl', 'this is Ruby', linebreak => 1);
      my $string = String::Diff::diff_regexp('this is Perl', 'this is Ruby', linebreak => 1);

    In diff and diff_merge methods the mark of the difference can be
    changed.

      my $diff = String::Diff::diff('this is Perl', 'this is Ruby',{
          remove_open => '<del>',
          remove_close => '</del>',
          append_open => '<ins>',
          append_close => '</ins>',
      });

    You can escape callback set to diff function and diff_merge function.

      use HTML::Entities
      my($diff_old, $diff_new) = String::Diff::diff(
          'this is <b>Perl</b>',
          'this is <b><BIG>R</BIG>uby</b>',
          remove_open => '<del>',
          remove_close => '</del>',
          append_open => '<ins>',
          append_close => '</ins>',
          escape       => sub { encode_entities($_[0]) },
      });
      is($diff_old, 'this is &lt;b&gt;<del>Perl</del>&lt;/b&gt;');
      is($diff_new, 'this is &lt;b&gt;<ins>&lt;BIG&gt;R&lt;/BIG&gt;uby</ins>&lt;/b&gt;');

METHODS
    diff_fully
          the list that divides diff according to the mark is returnd.

            my($old_string, $new_string) = String::Diff::diff_fully('this is Perl', 'this is Ruby');

    diff
          abd the mark of the deletion and the addition is given to the string.

    diff_merge
          old and new string is merged with diff.

    diff_regexp
          the regular expression to which old string and new string are matched with regexp is returned.

AUTHOR
    Kazuhiro Osawa <ko@yappo.ne.jp>

SEE ALSO
    Algorithm::Diff

LICENSE
    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.