get directory from file path c++

Question

What is the simplest way to get the directory that a file is in? I\'m using this to find the working directory.

string filename = \"C:\\MyDirectory\\MyFile.b         


        

Answer 1

A very simple cross-platform solution (as adapted from this example for string::find_last_of):

std::string GetDirectory (const std::string& path)
{
    size_t found = path.find_last_of("/\\");
    return(path.substr(0, found));
}

This works for both cases where the slashes can be either backward or forward pointing (or mixed), since it merely looks for the last occurrence of either in the string path.

However, my personal preference is using the Boost::Filesystem libraries to handle operations like this. An example:

std::string GetDirectory (const std::string& path)
{
    boost::filesystem::path p(path);
    return(p.parent_path().string());
}

Although, if getting the directory path from a string is the only functionality you need, then Boost might be a bit overkill (especially since Boost::Filesystem is one of the few Boost libraries that aren't header-only). However, AFIK, Boost::Filesystem had been approved to be included into the TR2 standard, but might not be fully available until the C++14 or C++17 standard (likely the latter, based on this answer), so depending on your compiler (and when you're reading this), you may not even need to compile these separately anymore since they might be included with your system already. For example, Visual Studio 2012 can already use some of the TR2 filesystem components (according to this post), though I haven't tried it since I'm still using Visual Studio 2010...