KILL(2) | System Calls Manual | KILL(2) |
kill
—
#include <signal.h>
int
kill
(pid_t
pid, int sig);
kill
() function sends the signal given by
sig to pid, a process or a group
of processes. sig may be one of the signals specified in
sigaction(2) or it may be 0,
in which case error checking is performed but no signal is actually sent. This
can be used to check the validity of pid.
For a process to have permission to send a signal to a process designated by pid, the real or effective user ID of the receiving process must match that of the sending process or the user must have appropriate privileges (such as given by a set-user-ID program or the user is the super-user). A single exception is the signal SIGCONT, which may always be sent to any descendant of the current process.
For compatibility with System V, if the process number is negative but not -1, the signal is sent to all processes whose process group ID is equal to the absolute value of the process number. This is a variant of killpg(3).
If sig is equal to
0
, then no signal is sent to the process ID or
process group ID, but error checking is performed. This can be used to check
if the process ID or process group ID exist.
kill
() will fail and no signal will be sent if:
EINVAL
]EPERM
]ESRCH
]kill
() function is expected to conform to
IEEE Std 1003.1-1990 (“POSIX.1”).
July 9, 2014 | NetBSD 9.2 |