Originální popis anglicky:
killpg - send signal to a process group
Návod, kniha: Linux Programmer's Manual
int killpg(int pgrp, int sig);
sends the signal sig
to the process group pgrp
(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
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.
On success, zero is returned. On error, -1 is returned, and errno
- Sig is not a valid signal number.
- The process does not have permission to send the signal to
any of the target processes.
- No process can be found in the process group specified by
- The process group was given as 0 but the sending process
does not have a process group.
There are various differences between the permission checking in BSD-type
systems and SYSV-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.
SVr4, 4.4BSD (The killpg
function call first appeared in 4.0BSD).