Need help setting a flag once in sub.m when called from main.m

[Svante Signell]

Hi, 

I have the following problem:

I need to call a subfunction once from the main function, setting a flag
that it has been called. This should work as long as the workspace is
not cleared. I can solve it by a persistent variable in the subfunction
but it is not a nice solution.

Code below:

main.m:
<how to declare status here?>
status = sub(status);


sub.m:
function status = sub(status)
if ( strcmp (status,'yes') ~= 1)
  do stuff;
  printf ('sub.m: setting status flag')
  status = 'yes';
end

Calling main in the interpreter:

main
sub.m: setting status flag
main
<no output>
etc

clear all
main
sub.m: setting status flag
etc

Thanks,
Svante