How do i see the printed lines of a .exe file in Matlab?

Hello, i have the following problem: i wrote an test.exe, that i want to start from matlab with the parameter 3. So i use:

system('test.exe 3')

The test.exe has the following code: ...

printf('The parameter was %d!, is it right(y/n)=?',number); 
a=getchar();...

So when i start the test.exe from the windows cmd, it will first show me the text and waits for the char.

When i start the test.exe, it will show the text after the char was handed char over.

How can I solve this problem? Is it possible to start the windows cmd from matlab, so i can see the printed lines in the windows cmd window?

Thank you for Help and sorry for the bad english!

[dpb]

Do you want to interact with the process manually? If so, don't pass the argument.

[Fabian Bengl]

Yes i want to interact with the test.exe manually, the test.exe needs the char later on. But actually the user don't know what he has to do, because he doesn't see the text.

[dpb]

Will if you just pass

!test.exe

will, won't it?

It will also stall Matlab until the process exits.

It will be the DOS console that the text is in, however, NOT the ML command window if that is what you're expecting. There's no way to do the latter.

[Fabian Bengl]

When i pass

!test.exe 3

i have the same problem. No text until the char was handed over. I expect a DOS console, but there opens no DOS console.

[dpb]

Yeah, but you STILL passed the number in the command line...that's not in the suggested form.

Just use

!test.exe

[Fabian Bengl]

then the test.exe crashed, because no parameter was given to the file. (number)

...
printf('The parameter was %d!, is it right(y/n)=?',number); 
a=getchar();
...

Answer 1

[Greg]

This isn't something MATLAB can do with system calls. And it makes sense that way, because the entire point of system or ! is that you want MATLAB to run those commands for you in the background.

To accomplish your goal, you need a command that tells Windows to force something to the foreground:

system('start test.exe 3');

Beware that with the "start" directive, the operating environment (i.e., working directory, etc.) get a lot more convoluted. Further, this will still probably be useless to you, because I'm pretty sure MATLAB continues as soon as the call is made. It won't wait for the spawned command window to be closed, so you can't use anything with whatever it is that text.exe does.

[Fabian Bengl]

Thank you for your Answer. In my case this solves my problem, because the test.exe writes its output in a txt-file, which will be used in matlab. So before the txt-file will be loaded, the user will be asked, whether the exe-file finished writing.

Answer 2

[Walter Roberson]

You will need to use .NET for anything like this in Windows, see https://www.mathworks.com/matlabcentral/answers/414795-run-exe-with-an-input-file-and-close-upon-process-exit. You will need to figure out how you want to deal with standard input and standard output. The point is that with .NET it should be possible to talk interactively with an active process. See also https://www.mathworks.com/matlabcentral/answers/55214-reading-a-pipe-or-ouput-of-a-c-program-into-matlab#answer_315824

If you can rely upon the process always giving back the same prompts and that you do not need to make decisions or record what is sent to you for the purpose of determining what to send, then see also https://www.mathworks.com/matlabcentral/fileexchange/13851-popen-read-and-write

[Fabian Bengl]

Thank you, your topics solve the basic problem i have, but this exceeds my skill level. So in my case it is easier to use

system('start test.exe 3');