1;;; esh-arg.el --- argument processing 2 3;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 4;; 2005, 2006, 2007 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-arg) 26 27(eval-when-compile (require 'esh-maint)) 28 29(defgroup eshell-arg nil 30 "Argument parsing involves transforming the arguments passed on the 31command line into equivalent Lisp forms that, when evaluated, will 32yield the values intended." 33 :tag "Argument parsing" 34 :group 'eshell) 35 36;;; Commentary: 37 38;; Parsing of arguments can be extended by adding functions to the 39;; hook `eshell-parse-argument-hook'. For a good example of this, see 40;; `eshell-parse-drive-letter', defined in eshell-dirs.el. 41 42(defcustom eshell-parse-argument-hook 43 (list 44 ;; a term such as #<buffer NAME>, or #<process NAME> is a buffer 45 ;; or process reference 46 'eshell-parse-special-reference 47 48 ;; numbers convert to numbers if they stand alone 49 (function 50 (lambda () 51 (when (and (not eshell-current-argument) 52 (not eshell-current-quoted) 53 (looking-at eshell-number-regexp) 54 (eshell-arg-delimiter (match-end 0))) 55 (goto-char (match-end 0)) 56 (let ((str (match-string 0))) 57 (if (> (length str) 0) 58 (add-text-properties 0 1 '(number t) str)) 59 str)))) 60 61 ;; parse any non-special characters, based on the current context 62 (function 63 (lambda () 64 (unless eshell-inside-quote-regexp 65 (setq eshell-inside-quote-regexp 66 (format "[^%s]+" 67 (apply 'string eshell-special-chars-inside-quoting)))) 68 (unless eshell-outside-quote-regexp 69 (setq eshell-outside-quote-regexp 70 (format "[^%s]+" 71 (apply 'string eshell-special-chars-outside-quoting)))) 72 (when (looking-at (if eshell-current-quoted 73 eshell-inside-quote-regexp 74 eshell-outside-quote-regexp)) 75 (goto-char (match-end 0)) 76 (let ((str (match-string 0))) 77 (if str 78 (set-text-properties 0 (length str) nil str)) 79 str)))) 80 81 ;; whitespace or a comment is an argument delimiter 82 (function 83 (lambda () 84 (let (comment-p) 85 (when (or (looking-at "[ \t]+") 86 (and (not eshell-current-argument) 87 (looking-at "#\\([^<'].*\\|$\\)") 88 (setq comment-p t))) 89 (if comment-p 90 (add-text-properties (match-beginning 0) (match-end 0) 91 '(comment t))) 92 (goto-char (match-end 0)) 93 (eshell-finish-arg))))) 94 95 ;; backslash before a special character means escape it 96 'eshell-parse-backslash 97 98 ;; text beginning with ' is a literally quoted 99 'eshell-parse-literal-quote 100 101 ;; text beginning with " is interpolably quoted 102 'eshell-parse-double-quote 103 104 ;; argument delimiter 105 'eshell-parse-delimiter) 106 "*Define how to process Eshell command line arguments. 107When each function on this hook is called, point will be at the 108current position within the argument list. The function should either 109return nil, meaning that it did no argument parsing, or it should 110return the result of the parse as a sexp. It is also responsible for 111moving the point forward to reflect the amount of input text that was 112parsed. 113 114If no function handles the current character at point, it will be 115treated as a literal character." 116 :type 'hook 117 :group 'eshell-arg) 118 119;;; Code: 120 121;;; User Variables: 122 123(defcustom eshell-arg-load-hook '(eshell-arg-initialize) 124 "*A hook that gets run when `eshell-arg' is loaded." 125 :type 'hook 126 :group 'eshell-arg) 127 128(defcustom eshell-delimiter-argument-list '(?\; ?& ?\| ?\> ? ?\t ?\n) 129 "List of characters to recognize as argument separators." 130 :type '(repeat character) 131 :group 'eshell-arg) 132 133(defcustom eshell-special-chars-inside-quoting '(?\\ ?\") 134 "*Characters which are still special inside double quotes." 135 :type '(repeat character) 136 :group 'eshell-arg) 137 138(defcustom eshell-special-chars-outside-quoting 139 (append eshell-delimiter-argument-list '(?# ?! ?\\ ?\" ?\')) 140 "*Characters that require escaping outside of double quotes. 141Without escaping them, they will introduce a change in the argument." 142 :type '(repeat character) 143 :group 'eshell-arg) 144 145;;; Internal Variables: 146 147(defvar eshell-current-argument nil) 148(defvar eshell-current-modifiers nil) 149(defvar eshell-arg-listified nil) 150(defvar eshell-nested-argument nil) 151(defvar eshell-current-quoted nil) 152(defvar eshell-inside-quote-regexp nil) 153(defvar eshell-outside-quote-regexp nil) 154 155;;; Functions: 156 157(defun eshell-arg-initialize () 158 "Initialize the argument parsing code." 159 (define-key eshell-command-map [(meta ?b)] 'eshell-insert-buffer-name) 160 (set (make-local-variable 'eshell-inside-quote-regexp) nil) 161 (set (make-local-variable 'eshell-outside-quote-regexp) nil)) 162 163(defun eshell-insert-buffer-name (buffer-name) 164 "Insert BUFFER-NAME into the current buffer at point." 165 (interactive "BName of buffer: ") 166 (insert-and-inherit "#" buffer-name ">")) 167 168(defsubst eshell-escape-arg (string) 169 "Return STRING with the `escaped' property on it." 170 (if (stringp string) 171 (add-text-properties 0 (length string) '(escaped t) string)) 172 string) 173 174(defun eshell-resolve-current-argument () 175 "If there are pending modifications to be made, make them now." 176 (when eshell-current-argument 177 (when eshell-arg-listified 178 (let ((parts eshell-current-argument)) 179 (while parts 180 (unless (stringp (car parts)) 181 (setcar parts 182 (list 'eshell-to-flat-string (car parts)))) 183 (setq parts (cdr parts))) 184 (setq eshell-current-argument 185 (list 'eshell-convert 186 (append (list 'concat) eshell-current-argument)))) 187 (setq eshell-arg-listified nil)) 188 (while eshell-current-modifiers 189 (setq eshell-current-argument 190 (list (car eshell-current-modifiers) eshell-current-argument) 191 eshell-current-modifiers (cdr eshell-current-modifiers)))) 192 (setq eshell-current-modifiers nil)) 193 194(defun eshell-finish-arg (&optional argument) 195 "Finish the current argument being processed." 196 (if argument 197 (setq eshell-current-argument argument)) 198 (throw 'eshell-arg-done t)) 199 200(defsubst eshell-arg-delimiter (&optional pos) 201 "Return non-nil if POS is an argument delimiter. 202If POS is nil, the location of point is checked." 203 (let ((pos (or pos (point)))) 204 (or (= pos (point-max)) 205 (memq (char-after pos) eshell-delimiter-argument-list)))) 206 207;; Argument parsing 208 209(defun eshell-parse-arguments (beg end) 210 "Parse all of the arguments at point from BEG to END. 211Returns the list of arguments in their raw form. 212Point is left at the end of the arguments." 213 (save-excursion 214 (save-restriction 215 (goto-char beg) 216 (narrow-to-region beg end) 217 (let ((inhibit-point-motion-hooks t) 218 (args (list t)) 219 after-change-functions 220 delim) 221 (remove-text-properties (point-min) (point-max) 222 '(arg-begin nil arg-end nil)) 223 (if (setq 224 delim 225 (catch 'eshell-incomplete 226 (while (not (eobp)) 227 (let* ((here (point)) 228 (arg (eshell-parse-argument))) 229 (if (= (point) here) 230 (error "Failed to parse argument '%s'" 231 (buffer-substring here (point-max)))) 232 (and arg (nconc args (list arg))))))) 233 (if (listp delim) 234 (throw 'eshell-incomplete delim) 235 (throw 'eshell-incomplete 236 (list delim (point) (cdr args))))) 237 (cdr args))))) 238 239(defun eshell-parse-argument () 240 "Get the next argument. Leave point after it." 241 (let* ((outer (null eshell-nested-argument)) 242 (arg-begin (and outer (point))) 243 (eshell-nested-argument t) 244 eshell-current-argument 245 eshell-current-modifiers 246 eshell-arg-listified) 247 (catch 'eshell-arg-done 248 (while (not (eobp)) 249 (let ((result 250 (or (run-hook-with-args-until-success 251 'eshell-parse-argument-hook) 252 (prog1 253 (char-to-string (char-after)) 254 (forward-char))))) 255 (if (not eshell-current-argument) 256 (setq eshell-current-argument result) 257 (unless eshell-arg-listified 258 (setq eshell-current-argument 259 (list eshell-current-argument) 260 eshell-arg-listified t)) 261 (nconc eshell-current-argument (list result)))))) 262 (when (and outer eshell-current-argument) 263 (add-text-properties arg-begin (1+ arg-begin) 264 '(arg-begin t rear-nonsticky 265 (arg-begin arg-end))) 266 (add-text-properties (1- (point)) (point) 267 '(arg-end t rear-nonsticky 268 (arg-end arg-begin)))) 269 (eshell-resolve-current-argument) 270 eshell-current-argument)) 271 272(defsubst eshell-operator (&rest args) 273 "A stub function that generates an error if a floating operator is found." 274 (error "Unhandled operator in input text")) 275 276(defsubst eshell-looking-at-backslash-return (pos) 277 "Test whether a backslash-return sequence occurs at POS." 278 (and (eq (char-after pos) ?\\) 279 (or (= (1+ pos) (point-max)) 280 (and (eq (char-after (1+ pos)) ?\n) 281 (= (+ pos 2) (point-max)))))) 282 283(defun eshell-quote-backslash (string &optional index) 284 "Intelligently backslash the character occuring in STRING at INDEX. 285If the character is itself a backslash, it needs no escaping." 286 (let ((char (aref string index))) 287 (if (eq char ?\\) 288 (char-to-string char) 289 (if (memq char eshell-special-chars-outside-quoting) 290 (string ?\\ char))))) 291 292(defun eshell-parse-backslash () 293 "Parse a single backslash (\) character, which might mean escape. 294It only means escape if the character immediately following is a 295special character that is not itself a backslash." 296 (when (eq (char-after) ?\\) 297 (if (eshell-looking-at-backslash-return (point)) 298 (throw 'eshell-incomplete ?\\) 299 (if (and (not (eq (char-after (1+ (point))) ?\\)) 300 (if eshell-current-quoted 301 (memq (char-after (1+ (point))) 302 eshell-special-chars-inside-quoting) 303 (memq (char-after (1+ (point))) 304 eshell-special-chars-outside-quoting))) 305 (progn 306 (forward-char 2) 307 (list 'eshell-escape-arg 308 (char-to-string (char-before)))) 309 ;; allow \\<RET> to mean a literal "\" character followed by a 310 ;; normal return, rather than a backslash followed by a line 311 ;; continuator (i.e., "\\ + \n" rather than "\ + \\n"). This 312 ;; is necessary because backslashes in Eshell are not special 313 ;; unless they either precede something special, or precede a 314 ;; backslash that precedes something special. (Mainly this is 315 ;; done to make using backslash on Windows systems more 316 ;; natural-feeling). 317 (if (eshell-looking-at-backslash-return (1+ (point))) 318 (forward-char)) 319 (forward-char) 320 "\\")))) 321 322(defun eshell-parse-literal-quote () 323 "Parse a literally quoted string. Nothing has special meaning!" 324 (if (eq (char-after) ?\') 325 (let ((end (eshell-find-delimiter ?\' ?\'))) 326 (if (not end) 327 (throw 'eshell-incomplete ?\') 328 (let ((string (buffer-substring-no-properties (1+ (point)) end))) 329 (goto-char (1+ end)) 330 (while (string-match "''" string) 331 (setq string (replace-match "'" t t string))) 332 (list 'eshell-escape-arg string)))))) 333 334(defun eshell-parse-double-quote () 335 "Parse a double quoted string, which allows for variable interpolation." 336 (when (eq (char-after) ?\") 337 (let* ((end (eshell-find-delimiter ?\" ?\" nil nil t)) 338 (eshell-current-quoted t)) 339 (if (not end) 340 (throw 'eshell-incomplete ?\") 341 (prog1 342 (save-restriction 343 (forward-char) 344 (narrow-to-region (point) end) 345 (let ((arg (eshell-parse-argument))) 346 (if (eq arg nil) 347 "" 348 (list 'eshell-escape-arg arg)))) 349 (goto-char (1+ end))))))) 350 351(defun eshell-parse-special-reference () 352 "Parse a special syntax reference, of the form '# arg>'." 353 (if (and (not eshell-current-argument) 354 (not eshell-current-quoted) 355 (looking-at "#<\\(buffer\\|process\\)\\s-")) 356 (let ((here (point))) 357 (goto-char (match-end 0)) 358 (let* ((buffer-p (string= (match-string 1) "buffer")) 359 (end (eshell-find-delimiter ?\< ?\>))) 360 (if (not end) 361 (throw 'eshell-incomplete ?\<) 362 (if (eshell-arg-delimiter (1+ end)) 363 (prog1 364 (list (if buffer-p 'get-buffer-create 'get-process) 365 (buffer-substring-no-properties (point) end)) 366 (goto-char (1+ end))) 367 (ignore (goto-char here)))))))) 368 369(defun eshell-parse-delimiter () 370 "Parse an argument delimiter, which is essentially a command operator." 371 ;; this `eshell-operator' keyword gets parsed out by 372 ;; `eshell-separate-commands'. Right now the only possibility for 373 ;; error is an incorrect output redirection specifier. 374 (when (looking-at "[&|;\n]\\s-*") 375 (let ((end (match-end 0))) 376 (if eshell-current-argument 377 (eshell-finish-arg) 378 (eshell-finish-arg 379 (prog1 380 (list 'eshell-operator 381 (cond 382 ((eq (char-after end) ?\&) 383 (setq end (1+ end)) "&&") 384 ((eq (char-after end) ?\|) 385 (setq end (1+ end)) "||") 386 ((eq (char-after) ?\n) ";") 387 (t 388 (char-to-string (char-after))))) 389 (goto-char end))))))) 390 391;;; arch-tag: 7f593a2b-8fc1-4def-8f84-8f51ed0198d6 392;;; esh-arg.el ends here 393