Rajaram Suryanarayanan <rajaram_linux@xxxxxxxxx> [2006-03-04]: > Hi, > > What is the difference between exit and _exit() ? man _exit: The function _exit() is like exit(), but does not call any functions registered with atexit() or on_exit(). Whether it flushes standard I/O buffers and removes temporary files created with tmpfile(3) is implementation dependent. On the other hand, _exit() does close open file descriptors, and this may cause an unknown delay, wait- ing for pending output to finish. If the delay is undesired, it may be useful to call functions like tcflush() before calling _exit(). Whether any pending I/O is can- celled, and which pending I/O may be cancelled upon _exit(), is implementation-depen- dent. > I studied in some google links that exit() is a C library wrapper and _exit() is the system call. Then what is sys_exit() ? The system calls should begin with "sys_" as per convention. Am I right ? sys_exit should be the system call in the kernel. The exit() or _exit() library functions do a syscall (software interrupt 70 on i386 and place the syscall number in %eax) and the kernel has a syscall table where it searches for the sycall number. So the name is irrelevant, only the number is important. By convention, sysalls in the kernel begin with sys_, right. Regards, Bernhard -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
