code for sam

fork_example.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

#define DEFAULT_PROCESS_COUNT 4

int process_count = DEFAULT_PROCESS_COUNT;

void do_work(int pid);

int main(int argc, char **argv) {  
  if (argc > 1) {
    process_count = atoi(argv[1]); // read the number of procs from commandline
  }
  
  printf("I'm starting up %d processes!\n", process_count);
  
  int pid[process_count];
  int i = 0;
  int is_parent = 0;
  
  for (i = 0; i < process_count; ++i) {
    
    pid[i] = fork();
    
    if (pid[i] != 0) {
      printf("This is Worker i %d\n",i);
      do_work(i);
      exit(EXIT_SUCCESS);
      break;
    } else {
      printf("This is Parent i %d\n",i);
      is_parent = 1;
      //printf("This is the Parent Process\n");
      
    }
  }
  
  if (is_parent) {
    for (i = 0; i < process_count; ++i) {
      waitpid(pid[i], NULL, 0);
    }
    
    printf("Done!\n");
  }

  
  return 0;
}


void do_work(int pid) {
  char cmd[1024];
  sprintf(cmd, "echo 'hello world' >> %d_output.txt", pid);
  system(cmd);
}