#!/usr/local/bin/perl
use strict;
use warnings;
use Term::ANSIColor 'colored';
use Getopt::Long 'GetOptions';
$Term::ANSIColor::EACHLINE = "\n";

# sdiff default is 130 columns
my $pivot = 65;
GetOptions(
    'pivot=i' => \ $pivot,
    'help'    => \ &help,
)
    or pod2usage( -verbose => 1 );

my $del_rx  = qr/^@{[ '.' x ( $pivot - 2 )]} < /;
my $diff_rx = qr/^@{[ '.' x ( $pivot - 2 )]} \| /;
my $add_rx  = qr/^@{[ '.' x ( $pivot - 2 )]} > /;

while (<>) {
    if ( /$del_rx/o ) {
        $_ = colored( $_, 'red on_black' );
    }
    elsif ( /$diff_rx/o ) {
        $_ = colored( $_, 'yellow on_black' );
    }
    elsif ( /$add_rx/o ) {
        $_ = colored( $_, 'green on_black' );
    }

    print;
}