_EXIT(2) Linux Programmer's Manual _EXIT(2) NAME _exit, _Exit - terminate the calling process SYNOPSIS #include <unistd.h> void _exit(int status); #include <stdlib.h> void _Exit(int status); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): _Exit(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L DESCRIPTION The function _exit() terminates the calling process "immediately". Any open file descriptors belonging to the process are closed; any children of the process are inherited by process 1, init, and the process's par- ent is sent a SIGCHLD signal. The value status is returned to the parent process as the process's exit status, and can be collected using one of the wait(2) family of calls. The function _Exit() is equivalent to _exit(). RETURN VALUE These functions do not return. CONFORMING TO POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD. The function _Exit() was introduced by C99. NOTES For a discussion on the effects of an exit, the transmission of exit status, zombie processes, signals sent, and so on, see exit(3). The function _exit() is like exit(3), but does not call any functions registered with atexit(3) or on_exit(3). Open stdio(3) streams are not flushed. On the other hand, _exit() does close open file descriptors, and this may cause an unknown delay, waiting for pending output to fin- ish. If the delay is undesired, it may be useful to call functions like tcflush(3) before calling _exit(). Whether any pending I/O is canceled, and which pending I/O may be canceled upon _exit(), is imple- mentation-dependent. C library/kernel differences In glibc up to version 2.3, the _exit() wrapper function invoked the kernel system call of the same name. Since glibc 2.3, the wrapper function invokes exit_group(2), in order to terminate all of the threads in a process. SEE ALSO execve(2), exit_group(2), fork(2), kill(2), wait(2), wait4(2), wait- pid(2), atexit(3), exit(3), on_exit(3), termios(3) COLOPHON This page is part of release 4.10 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/. Linux 2016-03-15 _EXIT(2) |