CreatePath - Full Path Creation (wstring version)-优快云博客

本文介绍了一个使用C++实现的递归函数，用于创建包含多个层级的路径。该函数能够处理尾随斜杠和网络位置，并通过调用SetLastError()来简化错误验证过程。

Environment: Visual C++

This is a simple function I wrote in order to deal with creating complete (multi-level) paths.

The function works recursively, and uses std::wstring , but can actaully work on any basic_string -based string. It can deal with trailing slashes (eg. "c:/temp/" vs. "c:/temp"), as well as network locations (eg. "//machine/shared").

You might notice the call to SetLastError() . The reason is to make it easy to verify what went wrong in case of an error - instead of handling exceptions and/or error strings, all you have to do is call GetLastError() if the function returns false .

You can use the function to make sure a directory exists before creating a file in it:

Here is the source code:

bool CreatePath(std::wstring &wsPath)

{

  DWORD attr;

  int pos;

  bool result = true;



  // Check for trailing slash:


  pos = wsPath.find_last_of(SLASH);

  if (wsPath.length() == pos + 1)  // last character is "/"

  {

    wsPath.resize(pos);

  }



  // Look for existing object:


  attr = GetFileAttributesW(wsPath.c_str());

  if (0xFFFFFFFF == attr)  // doesn't exist yet - create it!


  {

    pos = wsPath.find_last_of(SLASH);

    if (0 < pos)

    {

      // Create parent dirs:


      result = CreatePath(wsPath.substr(0, pos));

    }

    // Create node:


    result = result && CreateDirectoryW(wsPath.c_str(), NULL);

  }

  else if (FILE_ATTRIBUTE_DIRECTORY != attr)

  {  // object already exists, but is not a dir


    SetLastError(ERROR_FILE_EXISTS);

    result = false;

  }



  return result;

}