HP-UX Reference (11i v2 03/08) - 2 System Calls (vol 5)

k
kill(2) kill(2)
NAME
kill(), raise() - send a signal to a process or a group of processes
SYNOPSIS
#include <signal.h>
int kill(pid_t pid, int sig);
int raise(int sig);
DESCRIPTION
The kill() system call sends a signal to a process or a group of processes, as specified by pid. The sig-
nal to be sent is specified by sig and is either one from the list given in signal (2), or
0.
The
raise() system call sends a signal to the executing program. The signal to be sent is specified by
sig and is either one from the list given in signal (2), or
0.
If sig is
0 (the null signal), error checking is performed but no signal is actually sent. This can be used to
check the validity of pid .
The real or effective user ID of the sending process must match the real or saved user ID of the receiving
process unless the effective user ID of the sending process is a user who has appropriate privileges.
As a single special case, the continue signal
SIGCONT can be sent to any process that is a member of the
same session as the sending process.
The value
KILL_ALL_OTHERS
is defined in the file <sys/signal.h> and is guaranteed not to be the
ID of any process in the system or the negation of the ID of any process in the system.
If pid is greater than zero and not equal to
KILL_ALL_OTHERS
, sig is sent to the process whose process
ID is equal to pid. pid can equal
1 unless sig is SIGKILL or SIGSTOP.
If pid is
0, sig is sent to all processes excluding special system processes whose process group ID is equal
to the process group ID of the sender.
If pid is
-1 and the effective user ID of the sender is not a user who has appropriate privileges. sig is
sent to all processes excluding special system processes whose real or saved user ID is equal to the real or
effective user ID of the sender.
If pid is
-1 and the effective user ID of the sender is a user who has appropriate privileges, sig is sent to
all processes excluding special system processes.
If pid is
KILL_ALL_OTHERS
, kill() behaves much as when pid is equal to -1, except that sig is not
sent to the calling process.
If pid is negative but not
-1 or KILL_ALL_OTHERS
, sig is sent to all processes (excluding special system
processes) whose process group ID is equal to the absolute value of pid , and whose real and/or effective
user ID meets the constraints described above for matching user IDs.
RETURN VALUE
Upon successful completion, a value of
0 is returned. Otherwise, a value of -1 is returned and errno is
set to indicate the error.
ERRORS
If
kill() fails, no signal is sent. errno is set to one of the following values.
[EINVAL] sig is neither a valid signal number nor zero.
[EINVAL] sig is
SIGKILL or SIGSTOP and pid is 1 (process 1).
[EPERM] The user ID of the sending process is not a user who has appropriate privileges and
its real or effective user ID does not match the real or saved user ID of the receiving
process.
[EPERM] The sending and receiving processes are not in the same session and the real or
effective user ID does not match the real or saved user ID of the receiving process.
[ESRCH] No process or process group can be found corresponding to that specified by pid .
If
raise() fails, no signal is sent. errno is set to one of the following values.
[EINVAL] sig is neither a valid signal number nor zero.
HP-UX 11i Version 2: August 2003 − 1 − Hewlett-Packard Company Section 2−−127