Question

This code works on Windows XP at home but fails at work on 64bit Windows 7. The loop isn’t entered even once although there are more than 50 files in the supplied folder. Not only it doesn’t enter, it also returns ERROR_NO_MORE_FILES for GetLastError. Why?

string dir = "d:\\validfolder";
WIN32_FIND_DATA ffd;
HANDLE h = FindFirstFile(dir.c_str(), &ffd);
while(FindNextFile(h, &ffd))
{
// some operation
}
DWORD dw = GetLastError();// returns ERROR_NO_MORE_FILES

I tried Wow64DisableWow64FsRedirection but that has no effect.

Answer 1

You need to add a file wildcard to your dir:

string dir = "d:\\validfolder\\*";

For it to list the files in a directory. Otherwise you are only asking for information about the directory itself.

At least that’s how I read the documentation for FindFirstFile

To examine a directory that is not a root directory, use the path to
that directory, without a trailing backslash. For example, an argument
of “C:\Windows” returns information about the directory “C:\Windows”,
not about a directory or file in “C:\Windows”. To examine the files
and directories in “C:\Windows”, use an lpFileName of “C:\Windows*”.

I don’t know why it’s working for you on XP