lisp/eshell/esh-opt.el

   1 ;;; esh-opt.el --- command options processing
   2
   3 ;; Copyright (C) 1999, 2000, 2002, 2003, 2004,
   4 ;;   2005, 2006 Free Software Foundation, Inc.
   5
   6 ;; Author: John Wiegley <johnw@gnu.org>
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23 ;; Boston, MA 02110-1301, USA.
  24
  25 (provide 'esh-opt)
  26
  27 (eval-when-compile (require 'esh-maint))
  28
  29 (defgroup eshell-opt nil
  30   "The options processing code handles command argument parsing for
  31 Eshell commands implemented in Lisp."
  32   :tag "Command options processing"
  33   :group 'eshell)
  34
  35 ;;; Commentary:
  36
  37 ;;; User Functions:
  38
  39 (defmacro eshell-eval-using-options (name macro-args
  40                                           options &rest body-forms)
  41   "Process NAME's MACRO-ARGS using a set of command line OPTIONS.
  42 After doing so, settings will be stored in local symbols as declared
  43 by OPTIONS; FORMS will then be evaluated -- assuming all was OK.
  44
  45 The syntax of OPTIONS is:
  46
  47   '((?C  nil         nil multi-column    \"multi-column display\")
  48     (nil \"help\"      nil nil             \"show this usage display\")
  49     (?r  \"reverse\"   nil reverse-list    \"reverse order while sorting\")
  50     :external \"ls\"
  51     :usage \"[OPTION]... [FILE]...
  52   List information about the FILEs (the current directory by default).
  53   Sort entries alphabetically across.\")
  54
  55 `eshell-eval-using-options' returns the value of the last form in
  56 BODY-FORMS.  If instead an external command is run, the tag
  57 `eshell-external' will be thrown with the new process for its value.
  58
  59 Lastly, any remaining arguments will be available in a locally
  60 interned variable `args' (created using a `let' form)."
  61   `(let ((temp-args
  62           ,(if (memq ':preserve-args (cadr options))
  63                macro-args
  64              (list 'eshell-stringify-list
  65                    (list 'eshell-flatten-list macro-args)))))
  66      (let ,(append (mapcar (function
  67                             (lambda (opt)
  68                               (or (and (listp opt) (nth 3 opt))
  69                                   'eshell-option-stub)))
  70                            (cadr options))
  71                    '(usage-msg last-value ext-command args))
  72        (eshell-do-opt ,name ,options (quote ,body-forms)))))
  73
  74 ;;; Internal Functions:
  75
  76 (eval-when-compile
  77   (defvar temp-args)
  78   (defvar last-value)
  79   (defvar usage-msg)
  80   (defvar ext-command)
  81   (defvar args))
  82
  83 (defun eshell-do-opt (name options body-forms)
  84   "Helper function for `eshell-eval-using-options'.
  85 This code doesn't really need to be macro expanded everywhere."
  86   (setq args temp-args)
  87   (if (setq
  88        ext-command
  89        (catch 'eshell-ext-command
  90          (when (setq
  91                 usage-msg
  92                 (catch 'eshell-usage
  93                   (setq last-value nil)
  94                   (if (and (= (length args) 0)
  95                            (memq ':show-usage options))
  96                       (throw 'eshell-usage
  97                              (eshell-show-usage name options)))
  98                   (setq args (eshell-process-args name args options)
  99                         last-value (eval (append (list 'progn)
 100                                                  body-forms)))
 101                   nil))
 102            (error "%s" usage-msg))))
 103       (throw 'eshell-external
 104              (eshell-external-command ext-command args))
 105     last-value))
 106
 107 (defun eshell-show-usage (name options)
 108   "Display the usage message for NAME, using OPTIONS."
 109   (let ((usage (format "usage: %s %s\n\n" name
 110                        (cadr (memq ':usage options))))
 111         (extcmd (memq ':external options))
 112         (post-usage (memq ':post-usage options))
 113         had-option)
 114     (while options
 115       (when (listp (car options))
 116         (let ((opt (car options)))
 117           (setq had-option t)
 118           (cond ((and (nth 0 opt)
 119                       (nth 1 opt))
 120                  (setq usage
 121                        (concat usage
 122                                (format "    %-20s %s\n"
 123                                        (format "-%c, --%s" (nth 0 opt)
 124                                                (nth 1 opt))
 125                                        (nth 4 opt)))))
 126                 ((nth 0 opt)
 127                  (setq usage
 128                        (concat usage
 129                                (format "    %-20s %s\n"
 130                                        (format "-%c" (nth 0 opt))
 131                                        (nth 4 opt)))))
 132                 ((nth 1 opt)
 133                  (setq usage
 134                        (concat usage
 135                                (format "    %-20s %s\n"
 136                                        (format "    --%s" (nth 1 opt))
 137                                        (nth 4 opt)))))
 138                 (t (setq had-option nil)))))
 139       (setq options (cdr options)))
 140     (if post-usage
 141         (setq usage (concat usage (and had-option "\n")
 142                             (cadr post-usage))))
 143     (when extcmd
 144       (setq extcmd (eshell-search-path (cadr extcmd)))
 145       (if extcmd
 146           (setq usage
 147                 (concat usage
 148                         (format "
 149 This command is implemented in Lisp.  If an unrecognized option is
 150 passed to this command, the external version '%s'
 151 will be called instead." extcmd)))))
 152     (throw 'eshell-usage usage)))
 153
 154 (defun eshell-set-option (name ai opt options)
 155   "Using NAME's remaining args (index AI), set the OPT within OPTIONS.
 156 If the option consumes an argument for its value, the argument list
 157 will be modified."
 158   (if (not (nth 3 opt))
 159       (eshell-show-usage name options)
 160     (if (eq (nth 2 opt) t)
 161         (if (> ai (length args))
 162             (error "%s: missing option argument" name)
 163           (set (nth 3 opt) (nth ai args))
 164           (if (> ai 0)
 165               (setcdr (nthcdr (1- ai) args) (nthcdr (1+ ai) args))
 166             (setq args (cdr args))))
 167       (set (nth 3 opt) (or (nth 2 opt) t)))))
 168
 169 (defun eshell-process-option (name switch kind ai options)
 170   "For NAME, process SWITCH (of type KIND), from args at index AI.
 171 The SWITCH will be looked up in the set of OPTIONS.
 172
 173 SWITCH should be either a string or character.  KIND should be the
 174 integer 0 if it's a character, or 1 if it's a string.
 175
 176 The SWITCH is then be matched against OPTIONS.  If no matching handler
 177 is found, and an :external command is defined (and available), it will
 178 be called; otherwise, an error will be triggered to say that the
 179 switch is unrecognized."
 180   (let* ((opts options)
 181          found)
 182     (while opts
 183       (if (and (listp (car opts))
 184                  (nth kind (car opts))
 185                  (if (= kind 0)
 186                      (eq switch (nth kind (car opts)))
 187                    (string= switch (nth kind (car opts)))))
 188           (progn
 189             (eshell-set-option name ai (car opts) options)
 190             (setq found t opts nil))
 191         (setq opts (cdr opts))))
 192     (unless found
 193       (let ((extcmd (memq ':external options)))
 194         (when extcmd
 195           (setq extcmd (eshell-search-path (cadr extcmd)))
 196           (if extcmd
 197               (throw 'eshell-ext-command extcmd)
 198             (if (char-valid-p switch)
 199                 (error "%s: unrecognized option -%c" name switch)
 200               (error "%s: unrecognized option --%s" name switch))))))))
 201
 202 (defun eshell-process-args (name args options)
 203   "Process the given ARGS using OPTIONS.
 204 This assumes that symbols have been intern'd by `eshell-with-options'."
 205   (let ((ai 0) arg)
 206     (while (< ai (length args))
 207       (setq arg (nth ai args))
 208       (if (not (and (stringp arg)
 209                     (string-match "^-\\(-\\)?\\(.*\\)" arg)))
 210           (setq ai (1+ ai))
 211         (let* ((dash (match-string 1 arg))
 212                (switch (match-string 2 arg)))
 213           (if (= ai 0)
 214               (setq args (cdr args))
 215             (setcdr (nthcdr (1- ai) args) (nthcdr (1+ ai) args)))
 216           (if dash
 217               (if (> (length switch) 0)
 218                   (eshell-process-option name switch 1 ai options)
 219                 (setq ai (length args)))
 220             (let ((len (length switch))
 221                   (index 0))
 222               (while (< index len)
 223                 (eshell-process-option name (aref switch index) 0 ai options)
 224                 (setq index (1+ index)))))))))
 225   args)
 226
 227 ;;; Code:
 228
 229 ;;; arch-tag: 45c6c2d0-8091-46a1-a205-2f4bafd8230c
 230 ;;; esh-opt.el ends here