detect debug mode

is there a way to tell if your function has been called from the "k>>" debug prompt instead of the normal ">>" prompt?

Something like an "isdebug()" function??

Thanks

Ronan

Answer 1

[Daniel Shub]

I don't think there is a robust way to tell. For example, you can get the "k>>" prompt with a keyboard command and I have no idea how to tell if the keyboard command has been called.

If you just want to tell if you are at a standard break point you can probably check each item in dbstack against the breakpoints returned by dbstatus.

[Ronan]

Thanks Daniel

If there really is no builtin way then comparing the outputs of dbstack an dbstatus is a good suggestion. Can anyone foresee and problems with this??

R

Answer 2

[Jan]

You can use this to determine, if Matlab is currently in debug mode:

feature('IsDebugMode')

This replies 1 in debug mode, 0 otherwise. This is not documented and can change with the Matlab version.

[Daniel Shub]

I need to play around with the feature command more.

[Ronan]

Thanks Jan.

Just what I was after.

Ronan

[Adam Danz]

Unfortunately, this solution no longer seems to work (r2019b) unless the call to feature or system_dependent is invoked by "Evalulate Selection" (F9).

function test()
clc()
feature('IsDebugMode')
system_dependent('IsDebugMode')
end

Answer 3

[Julian]

I also needed an answer to this question! I was pleased just now to find here on Answers that feature('IsDebugMode') does the trick. Before turning to Answers I was looking in the MATLAB help, and came up with this alternative:

try
  dbup   % try going up the stack frame, works if in debug mode
  dbdown % back to where we started
  isDebugMode = true;
catch ME
  assert(strcmp(ME.identifier, 'MATLAB:dbOnlyInDebugMode'))
  isDebugMode = false;
end

Although the undocumented feature() is much neater, this is an alternative if you want to stay on official MATLAB.

[Adam Danz]

This solution fails in r2019b (I haven't tested it in earlier versions).

Debug commands are only supported when stopped in debug mode so when they are executed from within a script/function as you step through it in debug mode, it will cause an error the same error as when it's invoked from outside of debug mode ('MATLAB:dbOnlyInDebugMode').