$core_dumped = ($? >> 15) & 1;

00000000 00000000 CSSSSSSS EEEEEEEE

   >> 15

00000000 00000000 00000000 0000000C

   & 1

00000000 00000000 00000000 00000001 = 1
00000000 00000000 00000000 0000000C

##</code><code>##

$signal = ($? >> 8) & 127;

00000000 00000000 CSSSSSSS EEEEEEEE

   >> 8

00000000 00000000 00000000 CSSSSSSS

   & 127

00000000 00000000 00000000 01111111 = 127
00000000 00000000 00000000 0SSSSSSS

##</code><code>##

$signal = ($? & 0x7F00) >> 8;

00000000 00000000 CSSSSSSS EEEEEEEE

   & 0x00007F00

00000000 00000000 01111111 00000000 = 0x00007F00
00000000 00000000 0SSSSSSS 00000000

   >> 8

00000000 00000000 00000000 0SSSSSSS