#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int main(int argc, char **argv) {
  if (argc != 2) {
    fprintf(stderr, "Wrong argument count!\n");
    return 1;
  }

  int fd = open(argv[1],
                O_WRONLY | O_TRUNC | O_CREAT,
                0644);
  if (fd == -1) {
    perror("Opening the file failed");
    return 1;
  }

  close(1);
  dup(fd);
  close(fd);

  system("date '+%F %T'");
  write(STDOUT_FILENO, "Hello", 5);
  printf(" world!\n");

  return 0;
}