#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <iostream>

using namespace std;

#define FILE_NOT_EXIST -1
#define EXECUTABLE 0
#define NOT_EXECUTABLE 1

int check_executable(char *filename)
{
  struct stat buf;
  int j = stat(filename, &buf);
  if (j == (-1)) return FILE_NOT_EXIST;
  if (buf.st_mode & 0111) return EXECUTABLE;
  return NOT_EXECUTABLE;
}

main(int argc, char * argv[])
{
  if (argc != 2) {
    cerr << "Usage: a.out file\n";
    exit(1);
  }
  int ret = check_executable(argv[1]);
  if (ret == FILE_NOT_EXIST) {
    cout << "File " << argv[1] << " does not exist.\n";
  } else if (ret == EXECUTABLE) {
    cout << "File " << argv[1] << " is an executable.\n";
  } else 
    cout << "File " << argv[1] << " is NOT an executable.\n";
}