Re: Squid running check

From: Andrew Bartlett <>
Date: Tue, 05 Apr 2005 10:07:51 +1000

On Mon, 2005-03-14 at 18:00 +0100, Nickolay Pelov wrote:
> I noticed that squid checks if it is running by checking if pid file
> exists. I think it will be better to check if there is really process
> with that pid like:
> if(kill(pid,0)==0){//squid is running
> }else{ // no process
> //unlink the pid file
> }
> I don't know how kill is implemented in other operating systems but I'm
> sure that there is a way to check if process is running.

What Samba does on it's pid file is to check there is a fcntl() lock on
the file. That way, we know that the process with that PID is also
Samba, not a re-used PID.

Andrew Bartlett

Andrew Bartlett                      
Authentication Developer, Samba Team 
Student Network Administrator, Hawker College

Received on Mon Apr 04 2005 - 18:07:58 MDT

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