/*------------------------------------------------------------------*/
/* testsignalfork.c                                                 */
/* Author: Bob Dondero                                              */
/* Ignoring signals in the parent (but not the child) process.      */
/*------------------------------------------------------------------*/

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <sys/types.h>
#include <wait.h>

int main(int argc, char *argv[])
{
   void (*pfRet)(int);
   pid_t iPid;
   int i = 0;

   pfRet = signal(SIGINT, SIG_IGN);
   if (pfRet == SIG_ERR) {perror(argv[0]); return EXIT_FAILURE; }

   fflush(NULL);
   iPid = fork();
   if (iPid == -1) {perror(argv[0]); return EXIT_FAILURE; }

   if (iPid == 0)
   {
      pfRet = signal(SIGINT, SIG_DFL);
      if (pfRet == SIG_ERR) {perror(argv[0]); return EXIT_FAILURE; }

      for (;;)
      {
         printf("Child process:  %d\n", i);
         i++;
      }
      /* Never should reach this point. */
   }

   for (;;)
   {
      printf("Parent process:  %d\n", i);
      i++;
   }
   /* Never should reach this point. */
}

/* Sample execution:

$ gcc -Wall -ansi -pedantic testsignalfork.c -o testsignalfork

$ testsignalfork
Parent process:  0
Parent process:  1
...
Child process:  0
Child process:  1
...
^C                      <- Kills child process, but not parent process
Parent process:  12345
Parent process:  12346
...

*/