Unix signals handling in C

os-signals.c

/* 
 * File:   os-signals.c
 * Author: Emerson Ribeiro de Mello <mello@ifsc.edu.br>
 *
 * Created on 30 June 2016
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>

void signal_handler(int signal) {

    switch (signal) {
        case SIGHUP:
            printf("\nSIGHUP received - Finalizing....\n");
            exit(EXIT_SUCCESS);
        case SIGUSR1:
            printf("\nSIGUSR1 received - Finalizing....\n");
            exit(EXIT_SUCCESS);
        case SIGINT:
            printf("\nSIGINT received - Finalizing....\n");
            exit(EXIT_SUCCESS);
        case SIGTERM:
            printf("\nSIGTERM received - ok, I'm going to start cleaning the houseand and then exit...\n");
            exit(EXIT_SUCCESS);
        case SIGQUIT:
            printf("\nSIGQUIT received - Finalizing....\n");
            exit(EXIT_SUCCESS);
        default:
            fprintf(stderr, "\nCaught wrong signal: %d\n", signal);
            exit(EXIT_FAILURE);
    }
}

int main(int argc, char** argv) {

    // Handling Linux Signals
    if (signal(SIGHUP, signal_handler) == SIG_ERR) {
        perror("\nCan't catch SIGHUP\n");
    }
    if (signal(SIGQUIT, signal_handler) == SIG_ERR) {
        perror("\nCan't catch SIGQUIT\n");
    }
    if (signal(SIGUSR1, signal_handler) == SIG_ERR) {
        perror("\nCan't catch SIGUSR1\n");
    }
    if (signal(SIGTERM, signal_handler) == SIG_ERR) {
        perror("\nCan't catch SIGTERM\n");
    }
    if (signal(SIGINT, signal_handler) == SIG_ERR) {
        perror("\nCan't catch SIGINT\n");
    }
    int sair = 1;
    int pid = getpid();
    while(sair != 0){
        printf("\nPID: %d.\nTry:\n(1) Press CTRL+C\n(2) Press CTRL+\\\n", pid);
        printf("(3) kill -s USR1 PID\n(4) kill PID\n(5) kill -9 PID\n");
        sleep(3);
    }
    return EXIT_SUCCESS;
}