Question

I need to know which is the real path of a given path.

For example:

The real path is: d:\src\File.txt
And the user give me: D:\src\file.txt
I need as a result: d:\src\File.txt

Answer 1

You can use this function:

[DllImport("kernel32.dll", SetLastError=true, CharSet=CharSet.Auto)]
static extern uint GetLongPathName(string ShortPath, StringBuilder sb, int buffer);

[DllImport("kernel32.dll")]
static extern uint GetShortPathName(string longpath, StringBuilder sb, int buffer); 

protected static string GetWindowsPhysicalPath(string path)
{
        StringBuilder builder = new StringBuilder(255);

        // names with long extension can cause the short name to be actually larger than
        // the long name.
        GetShortPathName(path, builder, builder.Capacity);

        path = builder.ToString();

        uint result = GetLongPathName(path, builder, builder.Capacity);

        if (result > 0 && result < builder.Capacity)
        {
            //Success retrieved long file name
            builder[0] = char.ToLower(builder[0]);
            return builder.ToString(0, (int)result);
        }

        if (result > 0)
        {
            //Need more capacity in the buffer
            //specified in the result variable
            builder = new StringBuilder((int)result);
            result = GetLongPathName(path, builder, builder.Capacity);
            builder[0] = char.ToLower(builder[0]);
            return builder.ToString(0, (int)result);
        }

        return null;
}