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

Asked by Fabian Bengl on 14 Sep 2018
Latest activity Commented on by Fabian Bengl on 15 Sep 2018
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!

  6 Comments

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.
Yeah, but you STILL passed the number in the command line...that's not in the suggested form.
Just use
!test.exe
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();
...

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2 Answers

Answer by Greg
on 15 Sep 2018
Edited by Greg
on 15 Sep 2018
 Accepted Answer

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.

  1 Comment

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.

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Answer by Walter Roberson
on 15 Sep 2018

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

  1 Comment

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');

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