NAME

String::Diff

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;');
            
          

NAME

String::Diff - Simple diff to String

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 <yappo {@} shibuya {dot} pl>

SEE ALSO

Algorithm::Diff

LICENSE

Copyright 2008 (C) Kazuhiro Osawa

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

AUTHOR

Kazuhiro Osawa <yappo {@} shibuya {dot} pl>

COPYRIGHT AND LICENSE

This software is copyright (c) 2025 by Kazuhiro Osawa <yappo {@} shibuya {dot} pl>.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.