use POSIX qw[ :sys_wait_h ];;
$pid = open O, '| perl.exe -e"sleep 10; exit(123)"' or die $!;;
print waitpid( $pid, &WNOHANG ) while sleep 1;;
0
0
0
0
0
0
0
4360
-1
-1
-1
Terminating on signal SIGINT(2)