Re: pushd and popd for octave?

[fork]

Jordi Gutiérrez Hermoso <jordigh <at> gmail.com> writes:

> Why not make both of them be wrappers to a third function that has the
> persistent variable?

Voila: 


function currd = dirTraverse(op, fdir)
  %% currd = dirTraverse(op, fdir)
  %% 
  %% op's are 'pushd', 'popd', 'clears', 'show'

  %% DIRSTACK will hold the directories we traverse
  persistent DIRSTACK;
  
  %% make sure we have a DIRSTACK
  if ~exist(DIRSTACK)
    DIRSTACK = {};
  endif

  %% do stuff depending on op
  switch lower(op)
    case 'pushd'
      if nargin ~= 2
        print_usage();
      endif
      currd = pwd();
      cd(fdir);                 % can error out before pushing
      DIRSTACK(end+1) = currd;
    case 'popd'
      if isequal(DIRSTACK, {})
        error("dirTraverse: popd called with empty DIRSTACK\n")
      endif
      currd = pwd();
      cd(DIRSTACK(end){:});
      DIRSTACK(end) = [];
    case 'clears'
      DIRSTACK = {};
    case 'show'
      disp(DIRSTACK)
    otherwise
      warning("dirTraverse: bad op: %s", op)
      print_usage();
  endswitch

endfunction