#!/usr/local/bin/perl

use strict;
use warnings;

#mapping of ASCII to DOS
my %asc2dos = (131,159,149,250,150,196,161,173,162,155,163,156,165,157,170,166,171,174,172,170,176,248,177,241,178,253,183,249,186,167,187,175,188,172,189,171,191,168,196,142,197,143,198,146,199,128,201,144,209,165,214,153,220,154,223,225,224,133,225,160,226,131,228,132,229,134,230,145,231,135,232,138,233,130,234,136,235,137,236,141,237,161,238,140,239,139,241,164,242,149,243,162,244,147,246,148,247,246,249,151,250,163,251,150,252,129,255,152);

#create the reverse mapping (DOS to ASCII)
my %dos2asc;
foreach my $key (sort keys %asc2dos)
{
	$dos2asc{$asc2dos{$key}} = $key;
}

#here's a test:
#create a string with some accented characters
my $string = pack("C10",223,224,225,232,231,236,237,241,243,244);
print "ASCII string = $string\n";
$string = asc2dos($string);
print "DOS string = $string\n";
$string = dos2asc($string);
print "ASCII string = $string\n";

#convert ASCII extended characters to DOS extended characters
sub asc2dos
{
	my $str = shift;
	foreach my $i (0..length($str)-1)
	{
		my $val = ord substr($str,$i,1);
		substr($str,$i,1) = chr $asc2dos{$val} || $val;
	}
	return $str;
}

#convert DOS extended characters to ASCII characters
sub dos2asc
{
	my $str = shift;
	foreach my $i (0..length($str)-1)
	{
		my $val = ord substr($str,$i,1);
		substr($str,$i,1) = chr $dos2asc{$val} || $val;
	}
	return $str;
}