How to get Current Directory?

Question

Hello,

I've been doing this in C# and Delphi ,but C++ is evil.The purpose is to create a file in the current directory(where the executable is running).

My code:

LPTSTR NPath = NULL;
DWORD a = GetCurrentDirectory(MAX_PATH,NPath);
HANDLE hNewFile = CreateFile(NPath,GENERIC_WRITE,0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);

I get exception at GetCurrentDirectory().

Please tell me why I get an exception and how do I make it easier in C++?

Answer 1

GetCurrentDirectory does not allocate space for the result, it's up to you to do that.

TCHAR NPath[MAX_PATH];
GetCurrentDirectory(MAX_PATH, NPath);

Also, take a look at Boost.Filesystem library if you want to do this the C++ way.

Answer 2

I would recommend reading a book on C++ before you go any further, as from your other posts here you are simply making it up as you go along. Accelerated C++ by Koenig and Moo is excellent. And calling their favourite language "evil" is not likely to make the C++ experts here want to help you.

To get the executable path use GetModuleFileName:

char buffer[MAX_PATH]
GetModuleFileName( NULL, buffer, MAX_PATH );

Here's a C++ function that gets the directory without the file name:

#include <windows.h>
#include <string>
#include <iostream>
using namespace std;;

string ExePath() {
    char buffer[MAX_PATH];
    GetModuleFileName( NULL, buffer, MAX_PATH );
    string::size_type pos = string( buffer ).find_last_of( "\\/" );
    return string( buffer ).substr( 0, pos);
}

int main() {
    cout << "my directory is " << ExePath() << "\n";
}

Answer 3

You should provide a valid buffer placeholder. that is:

TCHAR s[100];
DWORD a = GetCurrentDirectory(100, s);

Answer 4

GetCurrentDirectory() gets the current directory which is where the exe is invoked from. To get the location of the exe, use GetModuleFileName(NULL ...). if you have the handle to the exe, or you can derive it from GetCommandLine() if you don't.

As Mr. Butterworth points out, you don't need a handle.

Answer 5

To find the directory where your executable is, you can use:

TCHAR szFilePath[_MAX_PATH];
::GetModuleFileName(NULL, szFilePath, _MAX_PATH);