use strict;
use warnings;

my $str = "\tthis is a sample string\nwith various white space characters\n";
my $str2 = $str;
$str2 =~ tr/\t \n/\0\1\2/;

$str2 =~ s/([\0\1\2])/('\t', '\s', "\\n\n")[ord($1)]/ge;
print $str."\n";
print $str2;