'Error when calling DOS' error

I have a tool created by using Matlab 2016, now I am using it with Matlab 2019. I got 'Error when calling DOS' error while running it. However when I go to the line where the error happens (the command for running a .bat file) and run the command manually, it works. How can I solve this problem? I copy the related part . I got the error at the last line

% run batch
if ~err
    %         command=['cd "' dir '" & "components.bat"'];
    command=[dir(1) ': & cd "' dir '" & "' filename '.bat"'];
    err=dos(command)

[Jan]

Do you get a complete error message or is 'Error when calling DOS' the contents of the the variable err? What does "when I go to the line" exactly mean?

[Cem TAGIT]

Hi, I attached the error window.

I try to say that I checked the line where I got the error which is the last line , err=dos(command).

the .bat file I run manually is "' filename '.bat"

[Jan]

If you use the debugger, you can step through the code line by line. I do not see, which line causes the display of the error message. Check, what the contents of err is.

[Image Analyst]

Well certainly you agree that dir should not be the variable name for the folder. I suggest she try my code below (scroll down for it).

Using their code, I made a file called mybatch.bat and just put "dir" into it to get a directory listing. I tested it with this code

dir = pwd;
filename = 'myBatch';
command=[dir(1) ': & cd "' dir '" & "' filename '.bat"']
status = dos(command)

and it ran fine, putting the directory listing into MATLAB's command window. If the file is not there, I get an error but not the error they got. I'm using R2021b.

Again, I suggest you try my more robust code below, which checks to make sure that the batch file exists before calling dos().

Answer 1

[Image Analyst]

dir is a built-in function name. Do NOT use it as the name of a variable. Use folder instead. Try this:

folder = 'C:\';
filename = 'myBatchFile.bat'
fullFileName = fullfile(folder, filename)
if ~isfile(fullFileName)
    errorMessage = sprintf('Error: file does not exist:\n%s')
    uiwait(errordlg(errorMessage));
    return;
end
commandLine = sprintf('%s: & cd "%s" & "%s"\n', folder(1), folder, filename)
err = dos(command)