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;
     }
 
##</code><code>##

Bit# 15 14 13 12 11 10 09 08  07 06 05 04 03 02 01 00
      |  |  |  |  |  |  |  |   |  |  |  |  |  |  |  |
     X7 X6 X5 X4 X3 X2 X1 X0  CD S6 S5 S4 S3 S2 S1 S0
      |                        |  |
      +-- exit code (8bit)     |  +-- signal code (7bit)  
                               |
                               +-- core-dumped flag

##</code><code>##

my $exit_status = int( $? / 256 ); # quick and dirty exit-state
                                   # decimal arithmetic so to speak
                                   # (works for positive numbers)