#include <stdio.h> #include <stdlib.h> #include <signal.h> void signalHandler(int); /* declare a function*/ int main(int argc,char** argv) { printf("Process id is %d\n",getpid());/*display the current process id */ signal(SIGHUP,signalHandler); /* register handler function for a specific signal value*/ signal(SIGINT,signalHandler); signal(SIGQUIT,signalHandler); while(1) { printf("running ...\n"); sleep(5);/* sleep 5 seconds before next iteration*/ } } void signalHandler(int signalNum) { switch(signalNum) { case 1: printf("Get a signal --SIGHUP %n"); break; case 2: printf("Get a signal --SIGINT %n"); break; case 3: printf("Get a signal --SIGQUIT %n"); break; } return; }