CS 456 - Systems Programming Spring 2024

Displaying ./code/feb08/fork4.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>

int main(int argc, char **argv){
	
   pid_t child_id = fork();

   if (child_id == -1) { 
      perror("fork"); 
      exit(EXIT_FAILURE);
   }

   if (child_id > 0) { 
     // We have a child! Get their exit code

     int status;
     int rt; 
     rt = waitpid( child_id, &status, 0 );   
     printf("waitpid return: %d\n", rt);

     // code not shown to get exit status from child
   } else { // In child ...
     // start calculation
     printf("In child: %d\n", child_id);
     exit(123);
   }

}