Sporadic file movement error

Sporadic file movement error

I have a program that is a launcher for a mod for a game. The launcher
works for most of the people who use it, including myself, but for some
there is a strange bug that really has me struggling to fix it, and
further more driving me absolutely mental!
The basic idea is that my mod files are contained in a folder, the
launcher iterates through these files, reads a certain byte of the file
and based on the result either moves the file, or moves the file and
writes some text to a certain file, then launches the game. Seemingly
simple.
The main launch function looks like this:
private void Launch()
{
using (StreamWriter writer = new StreamWriter(userScriptPath,
false, Encoding.Unicode))
{
foreach (string file in Directory.GetFiles(modFolderPath +
"\\Files\\", "*.pack"))
{
int p = GetPackType(file);
if (p == 3)
{
if (File.Exists(modFolderPath + "\\Files\\" +
Path.GetFileName(file)))
{
File.Move(modFolderPath + "\\Files\\" +
Path.GetFileName(file), dataPath + "\\" +
Path.GetFileName(file));
}
writer.WriteLine("mod \"" + Path.GetFileName(file) +
"\";");
}
else if (p == 4)
{
if (File.Exists(modFolderPath + "\\Files\\" +
Path.GetFileName(file)))
{
File.Move(modFolderPath + "\\Files\\" +
Path.GetFileName(file), dataPath + "\\" +
Path.GetFileName(file));
}
}
}
}
Process game = Process.Start(gamePath);
// There is code here that waits for a minute until the game
process is actually found, incase its slow starting up
game.WaitForExit();
RestorePacks(); // <- Method to put back the files after finishing
}
The problem some users are getting is that when launching the mod the game
launches but it appears as though the launcher doesn't move the files as
the game is still in its normal state, it was very hard to ascertain
exactly why this was happening as I had no way of debugging it on their
computers and the program was working fine for me and all of my test
users.
To try and find out what was going on I added a number of checks and some
logging to the launcher so that if the launcher didn't work, I'd at least
have an idea why. (Note that no errors are thrown for the users even when
it doesn't work)
The checks I added included using File.Exists() after attempting to move a
file to make sure it was actually moved, the logging kept a note of move
attempts and the result of this check to see if the file was actually
moved. I even added a specific if statement to the Process.Start function
checking specifically that a certain file was indeed in the required
location before launching the game. Finally before launching all of the
files in the folder where the mod files should now be are written to the
log.
All of the logs from users who the launcher didn't work for shared one
thing in common the program attempted to move the file, threw no error,
and then when checking that the file was indeed moved, the file appeared
to be there. But when reaching the point where all of the files in the
required directory are written to the log, only one of the required 30+
mod files appear to be in the directory.
An example output log looked something like this:
File moving: modfile1.txt
Checking if file is where we tried to move it to: Yes
File moving: modfile2.txt
Checking if file is where we tried to move it to: Yes
File moving: modfile3.txt
Checking if file is where we tried to move it to: Yes
Writing out all files in directory:
normalgamefile1.txt
normalgamefile2.txt
normalgamefile3.txt
modfile1.txt
After seeing this and noticing it was always only a single file that had
moved and no others, and also that the program did think the files were
where they where supposed to be, the confusion really started to kick in.
This is the method that reads the file to ascertain what type of file it is:
private int GetPackType(string path)
{
FileStream fs = File.OpenRead(path);
BinaryReader reader = new BinaryReader(fs);
reader.ReadChars(4);
int packType = reader.ReadInt32();
fs.Close();
fs.Dispose();
return packType;
}
As you can probably see, and what I've just noticed is that I've failed to
close/dispose of reader, and I'm guessing and somewhat hoping this might
be the cause of my problem. (Note I'm now using Using statements in this
method but can't test this fix for quite a while)
SO, if you've read this far thank you, my question is..
Firstly do you have any idea what the problem is? Could it be that reader
still might have the file open and has not closed and thus the file can't
move, IF SO then why does it work perfectly for me and most others, but
not for some? Surely a file still being used elsewhere would throw an
error?
I've gone through all the simple stuff like making sure the program is run
with administrator privileges, etc.
Thank you greatly for any help!