Checking processes without PIDs

[Dan Nelson]

In the last episode (Nov 27), jhall at vandaliamo.net said:
> I have written a script to determine if processes are running.  I am
> using, as an example,
> 
> ps -ax | grep -c postgrey
> 
> Ocassionally, I am receiving a notification a process is not running
> (and it varies which process I receive notifications for).  And, when
> checking, the process actually is running.
> 
> Is there a better way to determine if a process is running than using ps
> and grep?

Reading the program's pidfile and checking to see if that pid still
exists is the best way.  That only works if your program generates a
pidfile, though.  Most of the time they're in /var/run or a
subdirectory.  If it doesn't generate a pidfile, you can try the pgrep
command, which is better than a "ps|grep" combo because it won't ever
accidentally match itself.

-- 
	Dan Nelson
	dnelson at allantgroup.com