/* dup2ex.c
   Jim Plank
   CS360
   Dup lecture 

   Showing how dup2(fd, 1) redirects standard output to the file in fd. */

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

int main()
{
  int fd;
  char *s;

  fd = open("file4.txt", O_WRONLY | O_CREAT | O_TRUNC, 0666);

  if (dup2(fd, 1) < 0) { perror("dup2"); exit(1); }

  printf("Standard output now goes to file4.txt\n");

  close(fd);

  printf("It goes even after we closed file descriptor %d\n", fd);

  putchar('p'); putchar('u'); putchar('t'); putchar('c'); putchar('h');
  putchar('a'); putchar('r'); putchar(' '); putchar('w'); putchar('o');
  putchar('r'); putchar('k'); putchar('s'); putchar('\n');

  s = "And fwrite\n";

  fwrite(s, sizeof(char), strlen(s), stdout);

  fflush(stdout); 

  s = "And write\n";
  write(1, s, strlen(s));
  return 0;
}