thanks for the reply, field supposed to holds the latest value in share memory, $newvalue.

what confused me is that when child process is dead, parent will fork a new one, at that time I do see field of the object in parent holds the latest value of $newvalue since this section get executed: 

  if ($pid = fork) { #parent
$this->{'field'} = $newvalue;
$num_children++;
 print 'parent'.$$.'|'.$this->{'field'}."\n";
return;
}

[download]
so I expect the forked new child should also have that value.from my understanding of the fork, it will get a copy of the parent's var, filehandle,etc. right ? However, new child does not get the lastest $newvalue but get the value when parent first startup (parent never exit since this is a daemon which monitors child). so did I misunderstand the meaning of fork or something else ? btw, in the child section, I removed the tie $newvalue... so that $newvalue will always be the one in share memory.

In reply to Re^2: IPC and communication between Parent and Child Process by hengha
in thread IPC and communication between Parent and Child Process by hengha

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