The REAPER is part of the parent. So having waitpid() in only one place means having it only in REAPER().

Some replacement code to this foreach (@all_kids) loop:

while (@dead_kids <10)
{
   sleep(1);
}
print "all kids dead .. @dead_kids\n";
[download]

Update: Oh, I would also add use warnings; either by that statement, or a -w in the hash bang line. This has nothing to do with your current woes, but there are run time checks with warnings enabled that are useful. I leave them on unless some rare, very rare performance or other reason indicates otherwise.

Another Update: Was able to test some code...for some reason, when SIGCHLD happens, this causes the sleep to end. I don't know why. So there is a loop to restart the sleep every 1 seconds. try this code...have to run to an appointment...oh, exit 1 was caused by missing parens in while statement in the reaper. The sleep issue is the real puzzle here.

update: added readmore tag - updated code in later post

#!/usr/bin/perl -w

use strict;
use POSIX qw(:signal_h :errno_h :sys_wait_h);

$SIG{CHLD} = \&REAPER;

my (@all_kids, @dead_kids);
my @array = qw(a b c d e f g h);

for (1 .. 10) 
{
    die "Bad Fork! $!\n" if ( !defined(my $pid = fork()) );
      
    if ($pid ==0)   #I'm child
    {
        my $t=int(rand(5))+1;
        print "@array sleeping $t secs\n";
        sleep ($t);
        exit (0);  
    }
            
    push (@all_kids, $pid);    #I'm parent
    print "Starting another child process - $pid.\n";      
}

print "All child processes have started...\n";
print "kids: @all_kids\n";

my $count=0;
while ($count <20)
{
   sleep(1);
   $count++;
}

print "dead kids: @dead_kids\n";
print "All child processes are finished???\n";


sub REAPER 
{
   my $pid;
   while ( ($pid = waitpid(-1, WNOHANG)) > 0) #missed paren before
   {
      print "Process $pid exited.\n";
      push @dead_kids, $pid;
   }
   return;
}
[download]