#!/usr/bin/perl

#use Errno qw(EAGAIN);     # Gets you the EAGAIN symbol for looping on fork soft errors.
use POSIX ":sys_wait_h";   # Gets you the WNOHANG symbol, used in waitpid call.

$|=1;                      # Force all writing to STDOUT to be immediately auto-flushed.

$pid1 = fork;
# print "\nAfter the first fork, PID $$ shows \$pid1 =>$pid1<\n";
if (! defined $pid1) {die "Bizarre fork error.\n"}

if ($pid1==0) {            #  First child process


  exit;

} else {                   #  Parent process

  $pid2 = fork;
  if (! defined $pid2) {die "Bizarre fork error.\n"}

  if ($pid2==0) {          #  Second child process


    exit;

  } else {                   #  Parent process

    do {
      $kid = waitpid(-1,&WNOHANG);
      #  print "In reap loop, \$kid =>$kid< with exit status of >$?<\n" if $kid != 0;
      #  waitpid returns  0 if the child is still running
      #                  -1 if the child is no longer around (i.e. it's been reaped)
      #                  the $pid the first time we waitpid after the child dies.
    } until $kid == -1;
  }
}

print "\nHere when all children have been reaped.\n";