In general this is a very bad idea. First, processes might be runningg for a long time because they need to run for such a long time. If you kill the db-writer process of a DB it will not help the DB any but most probably corrupt the it beyond repair. If you kill a a systems daemon you might halt the system but most probably achieve nothing productive.

As a rule of thumb: never let scripts kill processes they have not spawned themselves. A script may kill a process it has started before in the background, but any other process should only be killed interactively! The reason is that admins (in general) are a lot smarter than scripts and can analyse the situation before they kill something vital.

This is, for an already bad idea, an even worse realisation. With kill -9 you are killing a process from outside without any chance to clean up: temporary files, shared memory segments, semaphores and any other item a process can allocate will remain there instead of being cleaned up by the exiting process.

If you really need to stop a process try with kill -15first, then wait for some time. Signal 15 will tell a process to kill itself and well-written processes honour this signal, cleaning up whatever they have allocated. (Processes not doing so should be moved to /dev/null instead of being run, their programmers should be beaten with a UNIX manual.) Only then you might use kill -9, but NEVER from script and never routinely. This is the desperate measure of last resort and should be used that way.

Finally, your choice of shells:
In AIX the default shell is ksh (in fact a ksh88). You can of course use any shell you want, but it is always a good idea to write scripts in a way so that they assume as little as possible. Don't make your scripts dependent on a non-standard shell without any necessity. Nothing in your script couldn't be written in ksh with the same ease as in bash.

I hope this helps.

bakunin