kill(pid_t pid, int sig)

• Send a signal to a specified process (either itself or another process).

signal

Usage

signal(int sig, void (*handler)(int));

• sig: Signal number (e.g., SIGINT, SIGTERM).
• handler: Pointer to a function taking int and returning void.
• void handler(int sig, siginfo_t *info, void *ucontext)
• Returns the previous handler pointer to handler, or SIG_ERR on failure.

Note

• Cannot catch or ignore SIGKILL and SIGSTOP.
• Always check if signal() returns SIG_ERR.

sigaction(signum, &sa, &old_sa)

sigprocmask(int how, &sigset, &old_sigset)

sigaddset(&sigset, signum)

sigemptyset(&sigset)

sigfillset(&sigset)