/* file: hw1.c 

   this program executes simple_fork program
   where input is taken from the file IN_FILE2

   Original author: Svetlana Mazurkova

   Seme details modified by T. P. Baker
*/

#define _XOPEN_SOURCE 500

#define IN_FILE2 "test2"
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>

extern void print_child_status (int status);

int main(int argc, char *argv[])
{
  pid_t pid;
  int fd;
  int status;
  char *argvv[2];

  argvv[0] = "simple_fork";
  argvv[1] = NULL;
  
  if ((pid = fork()) < 0) {
    fprintf (stderr, "fork error\n");
    exit (-1);
  }

  if (pid == 0 ) { /* executed by child process */
    /* redirect standard input file descriptor to IN_FILE2 */
    fd = open (IN_FILE2, O_RDONLY, 0);
    if (fd == -1) {
      perror ("open failed\n"); exit (-1);
    }
    close (0);
    if (dup2 (fd, 0) < 0) {
      perror ("dup2 failed"); exit(-1);
    }
    close (fd);
    if (execve ("simple_fork", argvv, NULL) <0) {
      perror ("execve failed"); exit (-1);
    }
  } else { /* executed by parent process */
    if (waitpid (pid, &status, 0) < 0){
      perror ("wait failed"); exit (-1);
    }
    print_child_status (status);
  }
  return 0;
}