Send a signal to a process or a group of processes
#include <sys/types.h> #include <signal.h> int kill( pid_t pid, int sig );
|If pid is:||Then sig is sent to:|
|> 0||The single process with that process ID|
|0||All processes that are in the same process group as the sending process|
|< 0||Every process that's a member of the process group -pid|
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The kill() function sends the signal sig to a process or group of processes specified by pid. If sig is zero, no signal is sent, but the pid is still checked for validity.
For a process to have permission to send a signal to a process, the real or effective user ID of the sending process must either:
If the value of pid causes sig to be generated for the sending process, and if sig isn't blocked, either sig or at least one pending unblocked signal is delivered before the kill function returns.
This call doesn't block. However, in the network case, lower priority threads may run.
Zero, or -1 if an error occurs (errno is set).
getpid(), killpg(), setsid(), sigaction(), signal(), SignalKill(), sigqueue()