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 calling process's process group.
(POSIX says: If
pgrp
is less than or equal to 1, the behavior 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.
RETURN VALUE
On success, zero is returned.
On error, -1 is returned, and
errno
is set appropriately.
ERRORS
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.
CONFORMING TO
SVr4, 4.4BSD (the
killpg()
function call first appeared in 4BSD), POSIX.1-2001.
NOTES
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.
On Linux,
killpg()
is implemented as a library function that makes the call
kill(-pgrp, sig).
This page is part of release 3.14 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.
