#!/usr/bin/perl -w
use strict;

my $all= pack "C*", 0..255;
print '$all has ', length($all), " bytes.\n";
my $in= $all;
$in =~ tr-/--d;
print '$in has ', length($in), " bytes.\n";
my $out= $in;
$out= chop($out) . $out;
print '$out has ', length($out), " bytes.\n";
my $count= eval "\$all =~ tr/$in/$out/";
warn "$@"   if  $@;
print "Translated $count bytes.\n";
print join( ",", unpack "C*", $all ), "\n";
__END__
$all has 256 bytes.
$in has 255 bytes.
$out has 255 bytes.
Translated 254 bytes.
255,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,
24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,
47,46,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,
68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,
90,92,91,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,
109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,
125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,
141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,
157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,
173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,
189,190,191,192,193,194,195,196,197,198,199,200,201,202,203,204,
205,206,207,208,209,210,211,212,213,214,215,216,217,218,219,220,
221,222,223,224,225,226,227,228,229,230,231,232,233,234,235,236,
237,238,239,240,241,242,243,244,245,246,247,248,249,250,251,252,
253,254