text: #include "apue.h"
  #include "fcntl.h"
  
  int main(int argc, char const *argv[])
  {
      if (argc != 2)
      {
          err_quit("usage: a.out <pathname>");
      }
  
      if (access(argv[1], R_OK) < 0)
      {
          err_ret("access error for %s", argv[1]);
      } else {
          printf("read access OK\n");
      }
  
      if (open(argv[1], O_RDONLY) < 0)
      {
          err_ret("open error for %s", argv[1]);
      } else {
          printf("open for reading OK\n");
      }
      exit(0);
  }