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c#linuxmonoexit-code
Brad Cunningham
Brad Cunningham

Reputation: 6501

Mono Process.Start returning ExitCode 255?

I have a simple C# Mono 2.10 application running on CentOS 5.5 that calls 

Process.Start("/path/to/myapp/myapp.exe","-someArgs");

I am able to get a process ID back and running with 

mono --trace=N:System.Diagnostics

Shows me a stack that seems to indicate that Process.Start returned true:

LEAVE: System.Diagnostics.Process:Start_noshell (System.Diagnostics.ProcessStartInfo,System.Diagnostics.Process)TRUE:1
LEAVE: System.Diagnostics.Process:Start_common (System.Diagnostics.ProcessStartInfo,System.Diagnostics.Process)TRUE:1
LEAVE: System.Diagnostics.Process:Start ()TRUE:1
LEAVE: (wrapper remoting-invoke-with-check) System.Diagnostics.Process:Start ()TRUE:1

Which I assume means the process was spawned without an exception like FileNotFound etc..

However, the process seems to exit immediately and the exit code I get is 255. I assume this is a Linux exit code with some obvious meaning but I can't find anything of use on the tubes.

When launching the exact same application directly via

mono /path/to/myapp/myapp.exe -someArgs

The application launches correctly without any exception and works as expected.

Any clue what I am screwing up?

Upvotes: 3

Views: 4705

Answers (4)

Alex Erygin
Alex Erygin

Reputation: 3230

You can start process using this overloading of Process.Start:

Process.Start("/bin/bash", "-c \"echo 'Hello World!'\"");

Don't know why, but it works.

Upvotes: 0

jonp
jonp

Reputation: 13600

Is the file /path/to/myapp/myapp.exe an executable file (chmod +x /path/to/myapp/myapp.exe)? Mono 2.10 does check to see if the process it's starting is a managed executable, and if so will implicitly use the currently executing mono to launch the new process, e.g. Mono's CreateProcess source. CreateProcess contains all the details, but among them:

If Process.Start still fails to start your process, then that's a probable mono bug and we'd love to have a bug reported for it. :-)

Upvotes: 4

jstedfast
jstedfast

Reputation: 38643

The problem is that Linux itself doesn't know that it needs to use Mono to run CIL .exe binaries, so it tries to use ld-linux.so as the loader, which for obvious reasons fails.

You need to invoke mono with /path/to/myapp.exe as an arg.

FWIW, an exit code of 255 is just "error".

Upvotes: 2

Reed Copsey
Reed Copsey

Reputation: 564861

Try launching "mono" as the process, and use "/path/to/myapp/myapp.exe -someArgs" as the command line arguments. That will cause the Process.Start to behave more like your normal application launch.

Upvotes: 2

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