How to tell if a process exists

[Doug Rudoff]

In a C program, how do you tell if a certain process exists? A
kill(0,pid) works only if you own the process (or you're root). It
seems like such a simple thing to request that it should be part of
the standard C libraries for unix, but I can't seem to find the right
thing to use.

The reason I need this is that I have a user interface that depends on
another prcoess to exist to run properly. The other process writes its
process id to a file and then I want the user interface to check to
see if that process id is still there. Is there a better way to do
this?

I'm running Ultrix 3.1D on a DECstation 3100.
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Doug Rudoff            Mobile Data International   Bothell, WA
(206) 487-5937         rudoff at mdi.com, uunet!mdisea!rudoff
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