killpg - 發送信號給進程組

內容簡介

#include <signal.h>

int killpg(int pgrp**, int** sig**);**

描述

killpg () sends the signal  sig  to the process group  pgrp . See  signal (7) for a list of signals. If  pgrp  is 0,  killpg () sends the signal to the sending process’s process group.

(POSIX says: If pgrp is less than or equal to 1, the behaviour is undefined.)

For a process to have permission to send a signal it must either be privileged (under Linux: have the CAP_KILL capability), or the real or effective user ID of the sending process must equal the real or saved set-user-ID of the target process. In the case of SIGCONT it suffices when the sending and receiving processes belong to the same session.

返回值

On success, zero is returned. On error, -1 is returned, and  errno  is set appropriately.

錯誤

標籤

描述

EINVAL

Sig is not a valid signal number.

EPERM

The process does not have permission to send the signal to any of the target processes.

ESRCH

No process can be found in the process group specified by pgrp.

ESRCH

The process group was given as 0 but the sending process does not have a process group.

注意

There are various differences between the permission checking in BSD-type systems and System V-type systems. See the POSIX rationale for  kill (). A difference not mentioned by POSIX concerns the return value EPERM: BSD documents that no signal is sent and EPERM returned when the permission check failed for at least one target process, while POSIX documents EPERM only when the permission check failed for all target processes.

遵循於

SVr4, 4.4BSD (The  killpg () function call first appeared in 4BSD), POSIX.1-2001.

另請參閱

• getpgrp (2)

• kill (2)

• signal (2)