/* CS360 Example Programs for the Atomic Lecture.
 *
 * James S. Plank
 * University of Tennessee
 * February, 2010
 *
 * This is openunique_2.c
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>

int main(int argc, char **argv)
{
  struct stat buf;
  int fd;
  char *filename;
  int iterations, i;
  int successful, unsuccessful, erroneous;

  if (argc != 3) {
    fprintf(stderr, "usage: openunique_2 filename iterations\n");
    exit(1);
  }
    
  filename = argv[1];
  iterations = atoi(argv[2]);
  successful = 0;
  unsuccessful = 0;
  erroneous = 0;

  for (i = 0; i < iterations; i++) {
    if (stat(argv[1], &buf) != 0) {
      fd = open(filename, O_WRONLY | O_CREAT, 0);
      if (fd <  0) {
        erroneous++;
      } else {
        close(fd);
        remove(filename);
        successful++;
      }
    } else {
      unsuccessful++;
    }
  }
  printf("  Successful: %5d\n", successful);
  printf("Unsuccessful: %5d\n", unsuccessful);
  printf("   Erroneous: %5d\n", erroneous);
  exit(0);
}