foreach $key (keys %argument)
{
        $argument{$key} =~ s/\\\\/\\/g;
}

##</code><code>##

#!/usr/bin/perl

use strict;
use Getopt::Std;

my (%argument, @contents, $contents, $key);

getopts('hd:s:', \%argument);

foreach $key (keys %argument)
{
        $argument{$key} =~ s/\\\\/\\/g;
}

if ($argument{h})
{
        helptext()
}else{
        open(FILEHANDLE, "< $ARGV[0]")
                or die "cannot open file: $!";
        $contents = do{local $/; <FILEHANDLE>};
        $contents =~ s/$argument{d}/$argument{s}/g;
        print $contents;
        close(FILEHANDLE);
}

sub helptext
{
print <<"EOT";
=====

syntax:
fts [-h] -d <string> [-s <string>] <file>

-h
        prints this help text and exits: invoking the help
        argument causes all other arguments to be discarded
        by this utility

-d
        takes string as input, searches for that string:
        replaces with string from -s or with an empty string
        if no -s argument is specified

-s
        takes string as input, substitutes it for string
        specified by the -d argument -- if not specified,
        text matching the -d argument will simply be
        deleted

<file>
        specifies [path and] name of file to take as input,
        on whose contents this utility operates

description:  fts (aka "file text substitution") takes a
file's contents as input and operates upon them, doing a
simple find and replace operation globally throughout the
file.  The results are dumped to STDOUT, so the original
file is untouched.  If you want the original file to be
overwritten with the new contents, use a shell redirect.

bugs:  There are no known bugs at this time.

credits:        Chad L. Perrin (author)
                Perlmonks community (contributors)

license:  This utility released under CCD CopyWrite.  See
following URL for details.

        http://ccd.apotheon.org

EOT
}