signal 信号处理

#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;
}