C++ - 判断文件夹(folder)是否存在(exist)

判断文件夹(folder)是否存在(exit)

本文地址: http://blog.csdn.net/caroline_wendy/article/details/21734915

写入程序, 需要在文件夹中写入数据, 如果文件夹不存在, 则无法写入, 在程序入口需要判断;

由于属于系统层, Windows的两种解决方法.

参考: http://stackoverflow.com/questions/8233842/how-to-check-if-directory-exist-using-c-and-winapi

1. GetFileAttributesA()函数

DWORD d = GetFileAttributesA(const char* filename); #include <windows.h>windows系统函数, 判断文件夹是否存在;

代码:

#include <iostream>#include <string>#include <windows.h>using namespace std;bool dirExists(const std::string& dirName_in){DWORD ftyp = GetFileAttributesA(dirName_in.c_str());if (ftyp == INVALID_FILE_ATTRIBUTES)return false;  //something is wrong with your path!if (ftyp & FILE_ATTRIBUTE_DIRECTORY)return true;   // this is a directory!return false;    // this is not a directory!}int main(void) {std::string folder("./Test");if (dirExists(folder)) {std::cout << "Folder : " << folder << " exist!" << std::endl;} else {std::cout << "Folder : " << folder << " doesn't exist!" << std::endl;}std::string nofolder("./TestNo");if (dirExists(nofolder)) {std::cout << "Folder : " << nofolder << " exist!" << std::endl;} else {std::cout << "Folder : " << nofolder << " doesn't exist!" << std::endl;}return 0;}

2. _access()函数

int access(const char *filename, int mode); #include <io.h>

mode设为0, 判断文件是否存在; 返回0, 文件存在;

代码:

#include <iostream>#include <string>#include <io.h>using namespace std;bool dirExists(const std::string& dirName_in){int ftyp = _access(dirName_in.c_str(), 0);if (0 == ftyp)return true;   // this is a directory!else return false;    // this is not a directory!}int main(void) {std::string folder("./Test");if (dirExists(folder)) {std::cout << "Folder : " << folder << " exist!" << std::endl;} else {std::cout << "Folder : " << folder << " doesn't exist!" << std::endl;}std::string nofolder("./TestNo");if (dirExists(nofolder)) {std::cout << "Folder : " << nofolder << " exist!" << std::endl;} else {std::cout << "Folder : " << nofolder << " doesn't exist!" << std::endl;}return 0;}