How do I get the directory that a program is running from?

Question

Is there a platform-agnostic and filesystem-agnostic method to obtain the full path of the directory from where a program is running using C/C++? Not to be confused with the

Answer 1

A library solution (although I know this was not asked for). If you happen to use Qt: QCoreApplication::applicationDirPath()

Answer 2

Here's code to get the full path to the executing app:

Windows:

int bytes = GetModuleFileName(NULL, pBuf, len);
return bytes ? bytes : -1;

Linux:

int bytes = MIN(readlink("/proc/self/exe", pBuf, len), len - 1);
if(bytes >= 0)
    pBuf[bytes] = '\0';
return bytes;

Answer 3

For Win32 GetCurrentDirectory should do the trick.

Answer 4

On Windows the simplest way is to use the _get_pgmptr function in stdlib.h to get a pointer to a string which represents the absolute path to the executable, including the executables name.

char* path;
_get_pgmptr(&path);
printf(path); // Example output: C:/Projects/Hello/World.exe

Answer 5

I know it is very late at the day to throw an answer at this one but I found that none of the answers were as useful to me as my own solution. A very simple way to get the path from your CWD to your bin folder is like this:

int main(int argc, char* argv[])
{
    std::string argv_str(argv[0]);
    std::string base = argv_str.substr(0, argv_str.find_last_of("/"));
}

You can now just use this as a base for your relative path. So for example I have this directory structure:

main
  ----> test
  ----> src
  ----> bin

and I want to compile my source code to bin and write a log to test I can just add this line to my code.

std::string pathToWrite = base + "/../test/test.log";

I have tried this approach on Linux using full path, alias etc. and it works just fine.

NOTE:

If you are on windows you should use a '\' as the file separator not '/'. You will have to escape this too for example:

std::string base = argv[0].substr(0, argv[0].find_last_of("\\"));

I think this should work but haven't tested, so comment would be appreciated if it works or a fix if not.