signal example

#include <stdio.h>
#include <signal.h>
#include <unistd.h>

void sig_handler(int signo) /* signal handler */
{
    if (signo == SIGINT)
        printf("received SIGINT\n");
}

int main(void)
{
    /* signal(3) can return only 3 dispositions i.e. SIG_DFL, SIG_IGN or SIG_ERR.  *
     * After main() calling this fx, whenever SIGINT is delivered to the process,  *
     * sig_handler fx will be invoked. This is called signal handler. And we can't *
     * check the current disposition without catching the signal, unless we        *
     * explicitly use sigaction(2).                                                *
     * Note that we can't catch or ignore SIGKILL and SIGSTOP.                     */
    if (signal(SIGINT, sig_handler) == SIG_ERR)
        fprintf(stderr, "can't catch SIGINT\n");
    /* A long wait so that we can easily issue a signal to this process. */
    while (1)
        sleep(1);

    return 0;
}