Lets say my default shell is bash and then i load up csh and then ksh. How would i exit csh without exiting ksh?

so basically i gone from bash > csh > ksh and i wish to close csh

Closing csh will terminate ksh.

kill -9 $PPID

In one word (well, two actually): you can't. You can't, because processes are organized like a tree. When you cut off a branch all the leaves on this branch are cut off too.

That means: you can exit the "csh" any way you want (sending it a KILL signal like was mentioned before is one way), but you will always exit the ksh too when you do so. The only way to circumvent this is to start the ksh in the background using "nohup". This will make the "leaf" to be its own branch starting from the main trunk (process "init") and hence leave it when you kill csh. You can not access this ksh directly any more, though, because it is not attached to any terminal any more. (This is fine for scripts writing to files, also for background processes, but will render interactive programs unusable.)

I hope this helps.

bakunin