How do you retrieve the original location of a mounted path?

Question

In C++, how can I retrieve the location of a mounted drive? for example, if I have mounted drive s: to c:\temp (using subst in the command line) "subst c:\temp s:" how can I get "c:\temp" by passing "s:"

I would also like to know how can it be done for a network drive. (if s: is mounted to "\MyComputer\Hello", then I want to retrieve "\MyComputer\Hello" and then to retrieve "c:\Hello" from that)

It might be a very easy question but I just couldn't find information about it.

Thanks,

Adam

Answer 1

If you've used SUBST, the API you want is QueryDosDevice. You can SUBST things yourself by using DefineDosDevice.

Answer 2

You can probably use the GetVolumeInformation function. From the documentation:

Symbolic link behavior

If the path points to a symbolic link, the function returns volume information for the target.

Haven't tested it myself, though.

Answer 3

To find the path of a mounted network share, you have to use the WNet APIs:

wstring ConvertToUNC(wstring sPath)
{
    WCHAR temp;
    UNIVERSAL_NAME_INFO * puni = NULL;
    DWORD bufsize = 0;
    wstring sRet = sPath;
    //Call WNetGetUniversalName using UNIVERSAL_NAME_INFO_LEVEL option
    if (WNetGetUniversalName(sPath.c_str(),
        UNIVERSAL_NAME_INFO_LEVEL,
        (LPVOID) &temp,
        &bufsize) == ERROR_MORE_DATA)
    {
        // now we have the size required to hold the UNC path
        WCHAR * buf = new WCHAR[bufsize+1];
        puni = (UNIVERSAL_NAME_INFO *)buf;
        if (WNetGetUniversalName(sPath.c_str(),
            UNIVERSAL_NAME_INFO_LEVEL,
            (LPVOID) puni,
            &bufsize) == NO_ERROR)
        {
            sRet = wstring(puni->lpUniversalName);
        }
        delete [] buf;
    }

    return sRet;;
}