NAME

Term::HiliteDiff - Highlights differences in text with ANSI escape codes

DESCRIPTION

Term::HiliteDiff prints or formats your input with the differences highlighted. You can choose to update your display in place or let things scroll past like following a log.

You can choose to parse things for Term::HiliteDiff or let it just do a plain character-by-character diff. My favorites are doing diffs on CSV or tab delimited data.

This module highlights differences between subsequent lines/records of text. It was directly inspired by the --difference mode provided by the watch(1) program on Linux.

SYNOPSIS

    # Prints a tab delimited file, with differences highlighted
    use Term::HiliteDiff 'hilite_diff';
    while ( <STDIN> ) {
        hilite_diff( [ split /\t/ ] );
    }

CONSTRUCTOR

The Term::HiliteDiff->new constructor returns a new Term::HiliteDiff::_obj object. It responds to the methods ->watch and ->hilite_diff.

hilite_diff( ARRAY REFERENCE )

hilite_diff( STRING, ... )

The hilite_diff function compares the previous input with the current input and prints the new input on a new line with any differences highlited.

This function accepts either a single array reference or a list of strings. The difference is whether your input will be parsed or not. There is no parsing with an array reference. Your strings are split into characters if you pass in a list of strings.

  while (<STDIN>) {
      print hilite_diff( $_ );
  }

In both cases the output joining the contents of your array reference or the list of strings by the $, variable.

  # Tab delimited input
  $, = "\t";
  while (<STDIN>) {
      print hilite_diff( [ split /$,/ ] );
  }

If this function is called in void context, the result will be printed to the currently selected filehandle. In list or scalar context the resultant string will just be returned.

Example 1:

  # prints differences to STDERR
  while (<STDIN>) {
      print STDERR hilite_diff( $_ );
  }

Example 2:

  # prints differences to the default handle
  while (<STDIN>) {
      hilite_diff( $_ );
  }

watch( ARRAY REFERENCE )

watch( STRING, ... )

This function operates just like hilite_diff with the exception that it attempts to always write its output over the same portion of screen real estate. This allows you to have output that continually refreshes in place.

I wrote this variant of hilite_diff so I could follow the changes inside a repeating data structure.

  # Watch 'a' increment inside the structure.
  use Data::Dumper 'Dumper';
  my @array = ( 1, 'a', 3 );
  while ( 1 ) {
      ++ $array[1]
      watch( Dumper( \ @array ) );
  }

AUTOMATIC EXPORTS

The watch and hilite_diff functions are exported when you've used this module from the command line.

  perl -MTerm::HiliteDiff -pe '$_ = hilite_diff( $_ )'

AUTHOR

Joshua ben Jore, <jjore@cpan.org>

BUGS

Please report any bugs or feature requests to bug-term-hilitediff@rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Term-HiliteDiff. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

ACKNOWLEDGEMENTS

COPYRIGHT & LICENSE

Copyright 2006 Joshua ben Jore, All Rights Reserved.

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