void _exit(int status);
#include <stdlib.h>
void _Exit(int status);
The value status is returned to the parent process as the process’s exit status, and can be collected using one of the wait() family of calls.
_Exit() 函式等同於 _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, waiting 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 cancelled, and which pending I/O may be cancelled upon _exit(), is implementation-dependent.