what is the difference between exit() and _exit()

vijaya_svk · 01-19-2008, 02:40 AM

Hi
I am using exit() and _exit(), can u please tell me the difference between these two and what happens when an int value is passed to it,
that is exit(100) or _exit(100)
and also exit(0) or _exit(0).

SciYro · 01-19-2008, 11:37 AM

If you would have bothered to look at the manual, or even use google, you could plainly see that the argument is the exit status of the program, and _exit() simply exits the program without doing a cleanup, while exit() calls the proper cleanup codes first.

ta0kira · 01-20-2008, 10:16 PM

You would use _exit from a fork normally so that it doesn't try to clean up external things that the parent would (such as temp files or shared memory.)
ta0kira

array lin · 01-21-2008, 01:37 AM

When use exit, it will do some cleanup work, like closing file descriptor, file stream and so on, while _exit() does not.

sundialsvcs · 01-21-2008, 06:11 PM

It is customary that routines whose names begin with one or more underscores are not intended for direct use by user-programs.