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_EXIT(2) Linux Programmer's Manual _EXIT(2)


_exit, _Exit - 呼び出し元のプロセスを終了させる


#include <unistd.h>

void _exit(int status);

#include <stdlib.h>

void _Exit(int status);

glibc 向けの機能検査マクロの要件 (feature_test_macros(7) 参照):




_exit() terminates the calling process "immediately". Any open file descriptors belonging to the process are closed. Any children of the process are inherited by init(1) (or by the nearest "subreaper" process as defined through the use of the prctl(2) PR_SET_CHILD_SUBREAPER operation). The process's parent is sent a SIGCHLD signal.

The value status & 0xFF is returned to the parent process as the process's exit status, and can be collected by the parent using one of the wait(2) family of calls.

関数 _Exit() は _exit() と等価である。




POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD. 関数 _Exit() は C99 で導入された。


exit の効果、終了状態の受渡し、ゾンビプロセス、シグナル送出などに ついての議論は、 exit(3) を参照すること。

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 finish. 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 implementation-dependent.

C ライブラリとカーネルの違い

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. (The raw _exit() system call terminates only the calling thread.)


execve(2), exit_group(2), fork(2), kill(2), wait(2), wait4(2), waitpid(2), atexit(3), exit(3), on_exit(3), termios(3)


この man ページは Linux man-pages プロジェクトのリリース 5.10 の一部である。プロジェクトの説明とバグ報告に関する情報は に書かれている。

2020-02-09 Linux