HI Jim, thanks for the reply. Once again aplologies for the text all being in one paragraph. No the script parses a .pid extension off a temporary directory and if it doesn't find a running process with that pid it clears down the directory. The problem I found when tracing the fail was a process with that id was still listed but with the arg DEFUNCT. You have got me thinking though, perhaps the transient error I found was due to the process id being reassigned to something else. That would explain why I am struggling to replicate it. I need to look at the code again and see if I can tighten it up so it finds the process name as well as the pid. One issue I am finding with these scripts is the ps args are often truncated to fit on screen and so the process name is not recoverable from the ps output. I think that is why they may have been written that way to start with. Do you know of anyway of forcing ps to output the whole line, wrapping if necessary? It would have to work on SUN and AIX..... Once again, thanks Jim, as always your very helpful