kill()

Purpose

kill() sends a signal to a process or process group.

Despite its name, it can send any signal, not only termination signals.

Header

#include <signal.h>
#include <sys/types.h>

Prototype

int kill(pid_t pid, int sig);

Minimal Example

if (kill(child_pid, SIGTERM) < 0) {
    perror("kill");
    return -1;
}

Common Pitfalls

• Assuming the target process exits immediately.
• Not checking permissions.
• Sending signals to the wrong process group by using negative PID values incorrectly.
• Forgetting to call waitpid() after terminating a child.

Related Topics

• Event Loop
• Network Programming
• IPC