/* file_age.c, by SoD-
 * Shows the age of a file in hours.
 */
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <time.h>

int main(int argc, char *argv[]) {
  struct stat filestats;

  if((argc != 2) || (stat(argv[1], &filestats) == -1)) {
    printf("-1\n");
    exit(EXIT_FAILURE);
  }

  printf("%d\n", (int)(difftime(time(NULL), filestats.st_mtime) / 3600));
  exit(EXIT_SUCCESS);
}