CODEWITHSUNDEEP
c#.netprocess
satori
satori

Reputation: 13

How to Force Windows to Start a Process as an EXE

If possible, how would you force C# code to run any given file as an exe even when the extension isn't .exe?

For example, my code extracts an exe from the program's resources into the user's roaming folder and starts it; GetRandomFileName() returns XXXXXX.XXX with Xs being random characters, but if I try to do:

string exePath = @"C:\Users\" + Environment.UserName + @"\AppData\Roaming\" + Path.GetRandomFileName();

using (FileStream exeFile = new FileStream(exePath, FileMode.CreateNew))
                            exeFile.Write(exeBytes, 0, exeBytes.Length);

process.StartInfo = processStartInfo;
processStartInfo.FileName = exePath;
Process.Start();

I get an error as Windows tries launching the program as a .XXX (whatever the random file extension may be).

Image of the error given:
enter image description here

Upvotes: 1

Views: 490

Answers (1)

Peter Duniho
Peter Duniho

Reputation: 70661

Just set UseShellExecute to false:

process.StartInfo = processStartInfo;
processStartInfo.FileName = exePath;
processStartInfo.UseShellExecute = false;
Process.Start();

By default, Process will use the Windows Shell to try to start your file. The Shell looks at the extension to figure out which program should actually run. Known-executable files are run directly, but any other file is checked for file extension associations. If none is present, you get the prompt to find a program to run it.

You can bypass all of that by setting UseShellExecute to false. That forces the Process class to just use the native CreateProcess() function directly. That function doesn't have any trouble starting any valid executable file, regardless of file name.

Upvotes: 6

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