// to compile:
// c++ test_file_exists.cpp -lboost_filesystem -lboost_system

#include <cstdlib>
#include <string>
#include <iostream>
#include <iomanip>
#include <boost/filesystem.hpp>
#include <sys/stat.h>
#include <fstream>

using namespace std;

bool stat_exists(const std::string& name) {
  struct stat buffer;   
  return (stat (name.c_str(), &buffer) == 0); 
}

bool stream_exists(const std::string &name)
{
    std::ifstream infile(name.c_str());
    return infile.good();
}

int main(int argc, char *argv[]) {
  if (argc != 2) {
    cerr << "usage: " << argv[0] << " pathname" << endl;
    exit (EXIT_FAILURE);
  }
  string pathname = argv[1];
  bool exist1 = boost::filesystem::exists(pathname);
  bool exist2 = stat_exists(pathname);
  bool exist3 = stream_exists(pathname);
  cout << "reply of boost::filesystem::exists: " << std::boolalpha << exist1 << endl;
  cout << "reply of stat_exists:               " << std::boolalpha << exist2 << endl;
  cout << "reply of stream_exists:             " << std::boolalpha << exist3 << endl;
  return EXIT_SUCCESS;
}