system('some_shell_command') >> 8 and die "Failed!";

# or else (same thing),

system('some_program');
if ($? >> 8 != 0) {
    die "Failed!";
}

##</code><code>##

system('foobar') == 0 or die "Failed!";

# or equivalently

system('foobar');
if ($? != 0) {
    die "Failed!";
}

##</code><code>##

if ($? == -1) {
    print "failed to execute: $!\n";
}
elsif ($? & 127) {
    printf "child died with signal %d, %s coredump\n",
      ($? & 127),  ($? & 128) ? 'with' : 'without';
}
else {
    printf "child exited with value %d\n", $? >> 8;
}