How do I get the directory that a program is runni

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 current working directory. (Please don't suggest libraries unless they're standard ones like clib or STL.)

(If there's no platform/filesystem-agnostic method, suggestions that work in Windows and Linux for specific filesystems are welcome too.)

Answer 1

Just to belatedly pile on here,...

there is no standard solution, because the languages are agnostic of underlying file systems, so as others have said, the concept of a directory based file system is outside the scope of the c / c++ languages.

on top of that, you want not the current working directory, but the directory the program is running in, which must take into account how the program got to where it is - ie was it spawned as a new process via a fork, etc. To get the directory a program is running in, as the solutions have demonstrated, requires that you get that information from the process control structures of the operating system in question, which is the only authority on this question. Thus, by definition, its an OS specific solution.

Answer 2

No, there's no standard way. I believe that the C/C++ standards don't even consider the existence of directories (or other file system organizations).

On Windows the GetModuleFileName() will return the full path to the executable file of the current process when the hModule parameter is set to NULL. I can't help with Linux.

Also you should clarify whether you want the current directory or the directory that the program image/executable resides. As it stands your question is a little ambiguous on this point.

Answer 3

For Win32 GetCurrentDirectory should do the trick.

Answer 4

For Windows system at console you can use system(dir) command. And console gives you information about directory and etc. Read about the dir command at cmd. But for Unix-like systems, I don't know... If this command is run, read bash command. ls does not display directory...

Example:

int main()
{
    system("dir");
    system("pause"); //this wait for Enter-key-press;
    return 0;
}

Answer 5

Boost Filesystem's initial_path() behaves like POSIX's getcwd(), and neither does what you want by itself, but appending argv[0] to either of them should do it.

You may note that the result is not always pretty--you may get things like /foo/bar/../../baz/a.out or /foo/bar//baz/a.out, but I believe that it always results in a valid path which names the executable (note that consecutive slashes in a path are collapsed to one).

I previously wrote a solution using envp (the third argument to main() which worked on Linux but didn't seem workable on Windows, so I'm essentially recommending the same solution as someone else did previously, but with the additional explanation of why it is actually correct even if the results are not pretty.

Answer 6

For relative paths, here's what I did. I am aware of the age of this question, I simply want to contribute a simpler answer that works in the majority of cases:

Say you have a path like this:

"path/to/file/folder"

For some reason, Linux-built executables made in eclipse work fine with this. However, windows gets very confused if given a path like this to work with!

As stated above there are several ways to get the current path to the executable, but the easiest way I find works a charm in the majority of cases is appending this to the FRONT of your path:

"./path/to/file/folder"

Just adding "./" should get you sorted! :) Then you can start loading from whatever directory you wish, so long as it is with the executable itself.

EDIT: This won't work if you try to launch the executable from code::blocks if that's the development environment being used, as for some reason, code::blocks doesn't load stuff right... :D

EDIT2: Some new things I have found is that if you specify a static path like this one in your code (Assuming Example.data is something you need to load):

"resources/Example.data"

If you then launch your app from the actual directory (or in Windows, you make a shortcut, and set the working dir to your app dir) then it will work like that. Keep this in mind when debugging issues related to missing resource/file paths. (Especially in IDEs that set the wrong working dir when launching a build exe from the IDE)