1 #include <iostream>
 2 #include <fstream>
 3
 4 using namespace std;
 5
 6 #define FILENAME "*.dat"  // 指定文件名
 7
 8 int main( void )
 9 {
10      fstream _file;
11      _file.open(FILENAME, ios::in);
12      if(!_file)
13      {
14           cout<<FILENAME<<"没有被创建!"<<endl;
15      }
16      else
17      {
18           cout<<FILENAME<<"已经存在!"<<endl;
19      }
20
21      cin.get();
22      return 0;
23 }

/* ACCESS.C: This example uses _access to check the* file named "ACCESS.C" to see if it exists and if* writing is allowed.*/#include  <io.h>
#include  <stdio.h>
#include  <stdlib.h>void main( void )
{/* Check for existence */if( (_access( "ACCESS.C", 0 )) != -1 ){printf( "File ACCESS.C exists " );/* Check for write permission */if( (_access( "ACCESS.C", 2 )) != -1 )printf( "File ACCESS.C has write permission " );}
}输出：
>>File ACCESS.C exists.
>>File ACCESS.C has write permission

#include "windows.h"
int main(int argc, char *argv[])
{WIN32_FIND_DATA  FindFileData;HANDLE hFind;printf ("Target file is %s. ", argv[1]);hFind = FindFirstFile(argv[1], &FindFileData);if (hFind == INVALID_HANDLE_VALUE){printf ("Invalid File Handle. Get Last Error reports %d ", GetLastError ());}else{printf ("The first file found is %s ", FindFileData.cFileName);FindClose(hFind);}return  0;
} 

// 目录是否存在的检查：
BOOL CheckFolderExist(const string &strPath)
{WIN32_FIND_DATA  FindFileData;BOOL bValue = false;HANDLE hFind = FindFirstFile(strPath.c_str(),  &FindFileData);if ((hFind != INVALID_HANDLE_VALUE) && (wfd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)){bValue = TRUE;  }FindClose(hFind);return bValue;
}

#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/filesystem/convenience.hpp>using namespace boost::filesystem;int GetFilePath(std::string &strFilePath)
{string strPath;int nRes = 0;//指定路径           strPath = "C:\";
path full_path( initial_path() );full_path = system_complete( path(strPath, native ) );//判断各级子目录是否存在，不存在则需要创建if ( !exists( full_path ) ){bool bRet = create_directories(full_path);if (false == bRet){return -1;}}strFilePath  =  full_path.native_directory_string();return 0;
}