man kill () - (OBSOLETE, REMOVED) send signal to a process
NAME
kill - (OBSOLETE, REMOVED) send signal to a process
SYNOPSIS
#include <sys/types.h> #include <signal.h> int kill pid_t pid, int sig);
DESCRIPTION
OBSOLETE and REMOVED. USE PTHREAD_KILL. The kill system can be used to send any signal to any process group or process. In RTLinux there is a single process and a single process group for each processor. The process group and the process identifier for that processor is the cpu number + 1 (so that we can handle the stupid 0 convention described below).
If pid is positive, then signal sig is sent to pid.
If pid equals 0, then sig is sent to every process in the process group of the current process. This is equivalent to sending the signal to the current process in RTLinux.
If pid equals -1, then sig is sent to every process except for the first one, from higher numbers in the process table to lower.
If pid is less than -1, then sig is sent to every process in the process group -pid.
If sig is 0, then no signal is sent, but error checking is still performed.
RETURN VALUE
On success, zero is returned. On error, -1 is returned, and errno is set appropriately.
ERRORS
- EINVAL
- An invalid signal was specified.
- ESRCH
- The pid or process group does not exit. Note that an existing process might be a zombie -- a process which already committed termination, but has not yet been wait()ed for.
- EPERM
- The process does not have permission to send the signal to any of the receiving processes. For a process to have permission to send a signal to process pid, it must either have root privileges, or the real or effective user ID of the sending process must equal the real or saved set-user-ID of the receiving process.
BUGS
It is impossible to send a signal to task number one, the init process, for which it has not installed a signal handler. This is done to assure the system is not brought down accidentally.
NOTES
In RTLinux, process number one is not special--it is just the process on processor 0. In a single processor system this is the only process identifier.
CONFORMING TO
SVr4, SVID, POSIX.1, X/OPEN, BSD 4.3