MATLAB: Try, Catch not working with system command.

catcherrorMATLABsystem commandtry

In my program I have the following block of code,
try
    !"C:\Program Files\MATLAB\R2016b\bin\matlab.exe" -r "foo"
catch
    warning('Directory was not found. Please locate the MATLAB R2016b installation.');
    [f2016, d2016] = uigetfile('*.exe','Locate MATLAB R2016b Executable');
    cmd = strcat('!"',d2016,f2016,'" -r "foo"');
    eval(cmd);
end
When I run it normally, everything works fine. But when I alter the path in try to create an error, the catch is never executed. Instead the program terminates and I'm left with "The system cannot find the path specified". This text isn't displayed as an error which is probably the issue, but is there any way to make my try, catch work? Or at least a workaround?

Best Answer

I recommend converting to use system()
path_to_matlab = '"C:\Program Files\MATLAB\R2016b\bin\matlab.exe"';
try_again = true;
while try_again
    try
        cmd = sprintf('"%s" -r "foo"', path_to_matlab);
        [status, result] = system(cmd);
        if status == 0; try_again = false; end
    catch ME
    end
    if try_again
        warning('MATLAB was not found. Please locate the MATLAB R2016b installation.');
        [f2016, d2016] = uigetfile('*.exe','Locate MATLAB R2016b Executable');
        if isnumeric(f2016)
          fprintf('Canceling');
          break
        end
        path_to_matlab = fullfile(d2016, f2016);
    end
  end
It is not clear why you are starting a new MATLAB session ?
You should consider using
if ispc()
   path_to_matlab = fullfile(matlabroot, 'bin', 'matlab.exe');
   file_select_ext = '*.exe');
else
   path_to_matlab = fullfile(matlabroot, 'bin', 'matlab');
   file_select_ext = '*');
end
try_again = true;
while try_again
    try
        cmd = sprintf('"%s" -r "foo"', path_to_matlab);
        [status, result] = system(cmd);
        if status == 0; try_again = false; end
    catch ME
    end
    if try_again
        warning('MATLAB was not found. Please locate the MATLAB R2016b installation.');
        [f2016, d2016] = uigetfile(file_select_ext, 'Locate MATLAB R2016b Executable');
        if isnumeric(f2016)
          fprintf('Canceling');
          break
        end
        path_to_matlab = fullfile(d2016, f2016);
    end
  end
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