在Google Groups 里面看到的一个讨论同时可以打开多少个文件进行处理的讨论。[代码]

向古人学习“识人”以及用友使用股权留住人才[世界经理人]

有要求的,想收徒弟[高手不要BS]

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2007/05/29 发表时间

18:20

3203

huzhangyou2002

开发语言

讨论蛮有意思！

引用

Hi
I am a student doing a project using C++ builder. I hava a problem in
opening a number of files more than 47, when run it only it create 46
file, Please help me to be able to create any number of files. Thanks
to your efforts.
Mohd Klaib

Example :

引用

I just wrote a program to test how many files can be opened by Windows
API - OpenFile. This program open more than 5000 files simultaneously.
So I think OpenFile can fit your request. The program as below:

//-------------------------------------------------------------------------------------------------- 
#include <iostream> 
#include <vector> 
#include <sstream> 
using namespace std; 
#include <windows.h>

void closeFilesByAPI(HANDLE fileHandle) 
{ 
   CloseHandle(fileHandle);

}

void howManyFilesCanBeOpenedByAPI() 
{ 
   vector<HANDLE> handleVector; 
   HANDLE fileHandle; 
   int count = 0; 
   DWORD writtenBytes; 
   do { 
      stringstream fileName; 
      fileName.clear(); 
      fileName << "file" << count; 
      fileHandle = CreateFile(fileName.str().c_str(), GENERIC_WRITE, 
FILE_SHARE_WRITE, NULL, CREATE_NEW, FILE_ATTRIBUTE_NORMAL 
+FILE_FLAG_RANDOM_ACCESS, NULL); 
      if (fileHandle == INVALID_HANDLE_VALUE) 
         break; 
      handleVector.push_back(fileHandle); 
      WriteFile(fileHandle, fileName.str().c_str(), 
fileName.str().size(), &writtenBytes, NULL); 
      cout << fileName.str() << '\r'; 
      count ++; 
   }while(fileHandle != INVALID_HANDLE_VALUE); 
   cout << "Total number of files opened by ofstream is: " << count << 
endl; 
   for_each(handleVector.begin(), handleVector.end(), 
closeFilesByAPI);

}