RE: [PHP] How to determine if a script instance is already runnin g?

> -----Original Message----- > From: Matt [mailto:datahead4@gmail.com] > Sent: Tuesday, August 02, 2005 10:45 AM > To: php-general@lists.php.net > Subject: Re: [PHP] How to determine if a script instance is already > running? > > > Perhaps "svscan" and its associated "daemontools" programs could be > used to monitor the script instead of relying on cron. > > http://cr.yp.to/daemontools.html > > On 8/2/05, André Medeiros <andre.caum@gmail.com> wrote: > > On Tue, 2005-08-02 at 15:09 +0100, Stut wrote: > > > André Medeiros wrote: > > > > Do like some services do: > > > > > > > > 1) Check if script.pid exists > > > > 2) If it doesn't > > > > 2.1) Write the process's PID onto the file > > > > (http://pt.php.net/manual/en/function.getmypid.php) > > > > 3) If it does > > > > 3.1) Die gracefully :) > > > > > > Personally I'd extend that slightly to have the process > touch the PID > > > file every so often and to check that it's been touched > recently when it > > > starts up. Alternatively use the ps shell command to check that a > > > process with that PID is still running, but that tends to > be less reliable. > > > > > > If the process does decide to continue in spite of the > PID file existing > > > it should issue a a shell kill command to kill that PID > in case it's > > > hung or a zombie. > > > > > > -Stut > > > > Excelent point! Thanks to all who replied. I'll let the list know how it works out. JM