🚀 go-pugleaf

Emacs 18.5[..7] : Bellow is a description of the bug, followed by some
  comments about the style of the Emacs code that handles command line
  arguments.


THE BUG:
   In the *info* (File: emacs,  Node: Command Switches) it says:

  >>   Note that the init file can get access to the command line argument
  >> values as the elements of a list in the variable `command-line-args'.
  >> (The arguments in the second table above will already have been
  >> processed and will not be in the list.)  The init file can override
  >> the normal processing of the other arguments by setting this variable.
                                                     ^^^^^^^^^^^^^^^^^^^^^

  In startup.el:
   (defun command-line ()
     (let ((args (cdr command-line-args))
 	........... CHOP "-q" AND "-u" AWAY FROM args .......
 	    (progn (load (if (eq system-type 'vax-vms)
 			     "sys$login:.emacs"
 			     (concat "~" init "/.emacs"))
 			 t t t)
 	........... args NOT USED HERE ......................
           (command-line-1 args)
 	.....))))


  Thus, when command-line processes the arguments, it does not care about
  the value of command-line-args that may have been set in the init-file !!!
    An immediate solution is to muck with the variable 'args in the init-file
  instead .... (at last, something good about dynamic binding).


STYLE COMMENTS:
  Looking through the code that handles command line arguments (in emacs.c
  and startup.el), I got the urge to grade it with an "F" !! (I have recently
  been a TA in an MIT course that stresses issues of good design, programming,
  etc. (6.170)).
    All this "argument skipping" leads to ugly code and also puts silly
  constraints on Emacs users (namely -- order of arguments). Why not just
  call procedures (or set flags) as the arguments are scanned (e.g. in 
  init_cmdargs() ). Why is there a need to "chop off" those leading arguments
  (e.g. "-batch"). (Same logic goes for startup.el).
    The existing code may save few milliseconds over what I proposed, but
  that happens only at start-up time !!
    The reason I looked into this was that I wanted to add some of my options
  to the command line (e.g. "emacs -foo"). I think that another clean way to
  do that is by adding some '(foo . my-foo) to command-switch-alist (in my
  init-file). This way is not mentioned in the *info* .

-- Boaz

========================================================
*   Boaz Ben-Zvi   (boaz@neutron.lcs.mit.edu)          *
*   MIT: NE43-526   Tel: (617) 253-6212                *
========================================================