lisp/eshell/esh-opt.el

   1 ;;; esh-opt.el --- command options processing
   2
   3 ;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
   4 ;;   2008  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 3 of the License, or
  13 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 (provide 'esh-opt)
  26
  27 (eval-when-compile (require 'esh-ext))
  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 ;;; User Functions:
  36
  37 (defmacro eshell-eval-using-options (name macro-args
  38                                           options &rest body-forms)
  39   "Process NAME's MACRO-ARGS using a set of command line OPTIONS.
  40 After doing so, settings will be stored in local symbols as declared
  41 by OPTIONS; FORMS will then be evaluated -- assuming all was OK.
  42
  43 The syntax of OPTIONS is:
  44
  45   '((?C  nil         nil multi-column    \"multi-column display\")
  46     (nil \"help\"      nil nil             \"show this usage display\")
  47     (?r  \"reverse\"   nil reverse-list    \"reverse order while sorting\")
  48     :external \"ls\"
  49     :usage \"[OPTION]... [FILE]...
  50   List information about the FILEs (the current directory by default).
  51   Sort entries alphabetically across.\")
  52
  53 `eshell-eval-using-options' returns the value of the last form in
  54 BODY-FORMS.  If instead an external command is run, the tag
  55 `eshell-external' will be thrown with the new process for its value.
  56
  57 Lastly, any remaining arguments will be available in a locally
  58 interned variable `args' (created using a `let' form)."
  59   (declare (debug (form form sexp body)))
  60   `(let ((temp-args
  61           ,(if (memq ':preserve-args (cadr options))
  62                macro-args
  63              (list 'eshell-stringify-list
  64                    (list 'eshell-flatten-list macro-args)))))
  65      (let ,(append (mapcar (function
  66                             (lambda (opt)
  67                               (or (and (listp opt) (nth 3 opt))
  68                                   'eshell-option-stub)))
  69                            (cadr options))
  70                    '(usage-msg last-value ext-command args))
  71        (eshell-do-opt ,name ,options (quote ,body-forms)))))
  72
  73 ;;; Internal Functions:
  74
  75 (defvar temp-args)
  76 (defvar last-value)
  77 (defvar usage-msg)
  78 (defvar ext-command)
  79 (defvar args)
  80
  81 (defun eshell-do-opt (name options body-forms)
  82   "Helper function for `eshell-eval-using-options'.
  83 This code doesn't really need to be macro expanded everywhere."
  84   (setq args temp-args)
  85   (if (setq
  86        ext-command
  87        (catch 'eshell-ext-command
  88          (when (setq
  89                 usage-msg
  90                 (catch 'eshell-usage
  91                   (setq last-value nil)
  92                   (if (and (= (length args) 0)
  93                            (memq ':show-usage options))
  94                       (throw 'eshell-usage
  95                              (eshell-show-usage name options)))
  96                   (setq args (eshell-process-args name args options)
  97                         last-value (eval (append (list 'progn)
  98                                                  body-forms)))
  99                   nil))
 100            (error "%s" usage-msg))))
 101       (throw 'eshell-external
 102              (eshell-external-command ext-command args))
 103     last-value))
 104
 105 (defun eshell-show-usage (name options)
 106   "Display the usage message for NAME, using OPTIONS."
 107   (let ((usage (format "usage: %s %s\n\n" name
 108                        (cadr (memq ':usage options))))
 109         (extcmd (memq ':external options))
 110         (post-usage (memq ':post-usage options))
 111         had-option)
 112     (while options
 113       (when (listp (car options))
 114         (let ((opt (car options)))
 115           (setq had-option t)
 116           (cond ((and (nth 0 opt)
 117                       (nth 1 opt))
 118                  (setq usage
 119                        (concat usage
 120                                (format "    %-20s %s\n"
 121                                        (format "-%c, --%s" (nth 0 opt)
 122                                                (nth 1 opt))
 123                                        (nth 4 opt)))))
 124                 ((nth 0 opt)
 125                  (setq usage
 126                        (concat usage
 127                                (format "    %-20s %s\n"
 128                                        (format "-%c" (nth 0 opt))
 129                                        (nth 4 opt)))))
 130                 ((nth 1 opt)
 131                  (setq usage
 132                        (concat usage
 133                                (format "    %-20s %s\n"
 134                                        (format "    --%s" (nth 1 opt))
 135                                        (nth 4 opt)))))
 136                 (t (setq had-option nil)))))
 137       (setq options (cdr options)))
 138     (if post-usage
 139         (setq usage (concat usage (and had-option "\n")
 140                             (cadr post-usage))))
 141     (when extcmd
 142       (setq extcmd (eshell-search-path (cadr extcmd)))
 143       (if extcmd
 144           (setq usage
 145                 (concat usage
 146                         (format "
 147 This command is implemented in Lisp.  If an unrecognized option is
 148 passed to this command, the external version '%s'
 149 will be called instead." extcmd)))))
 150     (throw 'eshell-usage usage)))
 151
 152 (defun eshell-set-option (name ai opt options)
 153   "Using NAME's remaining args (index AI), set the OPT within OPTIONS.
 154 If the option consumes an argument for its value, the argument list
 155 will be modified."
 156   (if (not (nth 3 opt))
 157       (eshell-show-usage name options)
 158     (if (eq (nth 2 opt) t)
 159         (if (> ai (length args))
 160             (error "%s: missing option argument" name)
 161           (set (nth 3 opt) (nth ai args))
 162           (if (> ai 0)
 163               (setcdr (nthcdr (1- ai) args) (nthcdr (1+ ai) args))
 164             (setq args (cdr args))))
 165       (set (nth 3 opt) (or (nth 2 opt) t)))))
 166
 167 (defun eshell-process-option (name switch kind ai options)
 168   "For NAME, process SWITCH (of type KIND), from args at index AI.
 169 The SWITCH will be looked up in the set of OPTIONS.
 170
 171 SWITCH should be either a string or character.  KIND should be the
 172 integer 0 if it's a character, or 1 if it's a string.
 173
 174 The SWITCH is then be matched against OPTIONS.  If no matching handler
 175 is found, and an :external command is defined (and available), it will
 176 be called; otherwise, an error will be triggered to say that the
 177 switch is unrecognized."
 178   (let* ((opts options)
 179          found)
 180     (while opts
 181       (if (and (listp (car opts))
 182                  (nth kind (car opts))
 183                  (if (= kind 0)
 184                      (eq switch (nth kind (car opts)))
 185                    (string= switch (nth kind (car opts)))))
 186           (progn
 187             (eshell-set-option name ai (car opts) options)
 188             (setq found t opts nil))
 189         (setq opts (cdr opts))))
 190     (unless found
 191       (let ((extcmd (memq ':external options)))
 192         (when extcmd
 193           (setq extcmd (eshell-search-path (cadr extcmd)))
 194           (if extcmd
 195               (throw 'eshell-ext-command extcmd)
 196             (if (characterp switch)
 197                 (error "%s: unrecognized option -%c" name switch)
 198               (error "%s: unrecognized option --%s" name switch))))))))
 199
 200 (defun eshell-process-args (name args options)
 201   "Process the given ARGS using OPTIONS.
 202 This assumes that symbols have been intern'd by `eshell-with-options'."
 203   (let ((ai 0) arg)
 204     (while (< ai (length args))
 205       (setq arg (nth ai args))
 206       (if (not (and (stringp arg)
 207                     (string-match "^-\\(-\\)?\\(.*\\)" arg)))
 208           (setq ai (1+ ai))
 209         (let* ((dash (match-string 1 arg))
 210                (switch (match-string 2 arg)))
 211           (if (= ai 0)
 212               (setq args (cdr args))
 213             (setcdr (nthcdr (1- ai) args) (nthcdr (1+ ai) args)))
 214           (if dash
 215               (if (> (length switch) 0)
 216                   (eshell-process-option name switch 1 ai options)
 217                 (setq ai (length args)))
 218             (let ((len (length switch))
 219                   (index 0))
 220               (while (< index len)
 221                 (eshell-process-option name (aref switch index) 0 ai options)
 222                 (setq index (1+ index)))))))))
 223   args)
 224
 225 ;;; Code:
 226
 227 ;; arch-tag: 45c6c2d0-8091-46a1-a205-2f4bafd8230c
 228 ;;; esh-opt.el ends here