#!/usr/bin/perl

use Term::ReadKey;

my $my_sequence = qr/\x1b\x02\z/;  # <CTRL>+<ALT>+B
my $key;
my $key_buf;

ReadMode 4;
while ($key ne 'q') {
    $key = ReadKey();
    printf "key=\\x%02x\n", ord($key);  # debug
    $key_buf .= $key;
    if ($key_buf =~ $my_sequence) {
        system "xmessage 'OH YA!'";
        last;
    }
};
ReadMode 0;