C# console program output problem

[JohnMoulding]

Hi,

I'm a newbie, so apologies for missing the obvious... and I have searched for an answer to this question, but all I get is "how to call an external program from a C# program" - which is not what I'm looking for.

I've written a C# console program that, after retrieving data from an SAP database, writes a simple (30 character) output string to a text file in a local directory. It works fine, and the fact that I can run it from the command line means it is easy to test.

We have a requirement to call my C# program from a Visual Objects program (not mine, don't know much about it). I do know that the Visual Objects program opens an Input Pipe to capture output from my C# program. So, instead of writing my result string to a text file, I simply need it to be captured by the calling program.

Do I just direct the output to the console (using Console.WriteLine("");) instead? Or is there another approach?

Thanks for all contributions,

John M.

[Shashi Sadasivan]

Hi,
sounds interesting on what you have to do.
But i think that putting the output onto a screen and then capturing what happened is not fesiable.
Not would it be fesiable to load it into the buffer and and then read the buffer (because you will have mouse movements, other programs outputs, misc activities, etc)

Either you should stick with letting the external program monitor the output file being written to and read any changes made to it.

OR.... you might make a DLL or use the exe file and get an output from it (which will require a few modifications in your application)

[Plater]

If this program captures the pipe for your program, then it probably captures the StandardOut (and maybe StandardError too?), you could try just ouputing the text to the console (Console.WriteLine() ) and see if it picks it up?

[JohnMoulding]

Hi,

thank you, yes, I could try that, but it's a nightmare to test the VO program, and I don't even know if it's working properly yet. I first have to know that my program is correct.

So, I'm thinking of creating a "test harness" program, written in C#, to test my own C# program! Sounds a bit crazy, but at least I can be sure that a value is being passed back to the calling program.

I think I need to use the System.Diagnostics.Process functionality, but I'm not certain how to make the calling program wait until the called program is finished. I don't want to just put in a "wait" loop with a timeout. I want the calling program to stop processing until the called program finishes - oh yes, and returns a value (not sure how to do this either).

Any more contributions gratefully received ;-),

John M.

[Plater]

Well you could do checks from the command line first?
If you ran this from the command line:

myprogram.exe > myoutput.txt
 

The output pipe of your program is re-directed to the myoutput.txt file. If that captures everything correctly I would think it would be fine?

Also, if myprogram.exe's main() function returns a "0" on good status or any other number on error (like old school program used to) then you can use:

ECHO %ERRORLEVEL% 
 

to see the value it returned.