Can script be configured to "exit on unhandled exception"? - matlab

Question

Is there a simple way to configure a MATLAB script so that it exits upon encountering an unhandled exception (as opposed to reverting to the REPL)?
The reason for this is that when executing many runs of a script in (unsupervised) batch mode, any script that fails should exit immediately, and not hang indifinitely at (unattended) interactive prompt.
IMPORTANT CLARIFICATION: this script is meant to be executed from the Unix command line, not from the MATLAB interactive prompt. More specifically, the script is to be invoked with
matlab -nodesktop -nosplash -nojvm -r myscript.m
The script should always terminate MATLAB after it has executed all its code, and return a status code reflecting its success (0) or failure (some non-zero integer).
I'm looking for a global setting (or a command-line flag) that can be put into effect without affecting the rest of the code.
IOW, I'm looking for something analogous to the -e flag available in some Unix shells (e.g. bash, zsh), which has the effect of aborting a script immediately whenever the return status of a statement is non-zero (meaning that the statement failed).
I know that I can wrap the entire body of a script with a try-catch, like this (for example):
try
exit_code = 0;
%
% BODY OF SCRIPT
%
catch exc
fprintf(2, 'CAUGHT EXCEPTION:\n');
fprintf(2, '%s(%d): %s\n', exc.stack.file, exc.stack.line, exc.message);
exit_code = 1;
end
exit(exit_code);
...but, as I said above, I'm looking for something simple, with no, or at most minimal, impact on the code.

Answer 1

The default behavior when an unhandled exception occurs is that information about the error will be printed to the command window and control will return to the command window. You should not be getting an interactive prompt from the error unless you've explicitly enabled it with dbstop if error or there is a try/catch with a keyboard command in the catch block. To just get a plain error rather than an interactive prompt you can use dbclear if error to disable this behavior. I would check your startup files to make sure that you don't have dbstop if error in there.
A try/catch pair is really the only way that this can be done. What you can do is wrap your calls to your script with another file and put the call to your script within a try/catch block. This has the added benefit that you don't have to modify the script itself, just the "runner".
Also you won't want to use exit as that completely exits MATLAB.
your_script.m
disp('Doing my thing')
error('Throwing an error!')
calling_script.m
for k = 1:100
try
% Call your other script and hope for no errors!
your_script
catch ME
% Print information about the error and continue
fprintf(2, 'CAUGHT EXCEPTION:\n');
fprintf(2, '%s(%d): %s\n', ME.stack.file, ME.stack.line, ME.message);
end
end
Update
Based upon the clarification that you've provided that you want to run this from the Unix command line, you'll still want to use something similar with a try/catch statement combined with exit. Again, you could do this in an external file as shown above
calling_script.m
code = 0;
try
your_script
catch ME
fprintf(2, 'CAUGHT EXCEPTION:\n');
fprintf(2, '%s(%d): %s\n', ME.stack.file, ME.stack.line, ME.message);
code = 1;
end
exit(code)