how to determine pipe process terminated or alive

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

advise me please, which is better or tell other ways

$p = open P, 'xxx|'
1) while (sysread P) {...}; close P; wait();
2) while (1) {...if($p==waitpid($p,WNOHANG)){last}}; close P;
[download]

My os is Debian. Both works but which is more correct

Comment on how to determine pipe process terminated or alive Download Code

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Re: how to determine pipe process terminated or alive by Zaxo (Archbishop) on Jun 16, 2007 at 15:22 UTC
Sometimes `sleep $interval while kill 0, $pid;` [download] is handy. It works for any process you have rights to signal, not just kids or parent. After Compline, Zaxo	[reply] [d/l]
Re: how to determine pipe process terminated or alive by kyle (Abbot) on Jun 18, 2007 at 02:57 UTC
Regarding your first example, when you close a pipe, a wait is done also, so your explicit `wait` is not necessary.	[reply] [d/l]