my %escape = map { ( chr($_) => eval '"\\'.chr($_).'"'||undef ) } 0 .. 127;

sub interpolate
{
        my ($s) = @_;

        $s =~ s/\\c(.)/chr(ord(lc($1))-ord('`'))/ge;
        $s =~ s/\\x([a-fA-F0-9]{2})/chr(hex($1))/ge;
        $s =~ s/\\0([0-9]{1,3})/chr(oct($1))/ge;
        $s =~ s/\\0/\0/g;

        $s =~ s/\\(.)/$escape{$1}/gs;

        return $s;
}