/* file: simple_fork2.c

   The addition of fflush() to simple_fork1.c
   eliminates problem of child inheriting uflushed output
   buffers from parent.

*/

#define _XOPEN_SOURCE 500

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

int main(int argc, char *argv[])
{

  char pathname [32];
  int i = 0;
  int outfildes;
  FILE *ofstream;

  if (argc < 2) {
    fprintf (stdout, "Please enter a filename or pathname: ");
    if (!gets (pathname)) {
      fprintf (stderr, "you must provide a filename\n");
      exit (-1);
    }
  } else strcpy (pathname, argv[1]);
  if ((outfildes =
       open (pathname, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR)) == -1) {
    fprintf (stderr,
      "could not open file \"%s\" for writing: %s\n",
      pathname, strerror (errno));
    exit (-2);
  }

  if (!(ofstream = fdopen (outfildes, "w"))) {
    perror ("could not open stream for writing");
    exit (-3);
  }

  while (i < 3) {
    fprintf (stdout, "i = %d in %d\n", i, getpid ());
    fprintf (ofstream, "i = %d in %d\n", i, getpid ());
    fflush (stdout);
    fork ();
    i++;
  }

  fclose (ofstream);
  close (outfildes);
  return 0;
}