1;;; esh-ext.el --- commands external to Eshell 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-ext) 26 27(eval-when-compile (require 'esh-maint)) 28(require 'esh-util) 29 30(defgroup eshell-ext nil 31 "External commands are invoked when operating system executables are 32loaded into memory, thus beginning a new process." 33 :tag "External commands" 34 :group 'eshell) 35 36;;; Commentary: 37 38;; To force a command to invoked external, either provide an explicit 39;; pathname for the command argument, or prefix the command name with 40;; an asterix character. Example: 41;; 42;; grep ; make invoke `grep' Lisp function, or `eshell/grep' 43;; /bin/grep ; will definitely invoke /bin/grep 44;; *grep ; will also invoke /bin/grep 45 46;;; User Variables: 47 48(defcustom eshell-ext-load-hook '(eshell-ext-initialize) 49 "*A hook that gets run when `eshell-ext' is loaded." 50 :type 'hook 51 :group 'eshell-ext) 52 53(defcustom eshell-binary-suffixes exec-suffixes 54 "*A list of suffixes used when searching for executable files." 55 :type '(repeat string) 56 :group 'eshell-ext) 57 58(defcustom eshell-force-execution nil 59 "*If non-nil, try to execute binary files regardless of permissions. 60This can be useful on systems like Windows, where the operating system 61doesn't happen to honor the permission bits in certain cases; or in 62cases where you want to associate an interpreter with a particular 63kind of script file, but the language won't let you but a '#!' 64interpreter line in the file, and you don't want to make it executable 65since nothing else but Eshell will be able to understand 66`eshell-interpreter-alist'." 67 :type 'boolean 68 :group 'eshell-ext) 69 70(defun eshell-search-path (name) 71 "Search the environment path for NAME." 72 (if (file-name-absolute-p name) 73 name 74 (let ((list (parse-colon-path (getenv "PATH"))) 75 suffixes n1 n2 file) 76 (while list 77 (setq n1 (concat (car list) name)) 78 (setq suffixes eshell-binary-suffixes) 79 (while suffixes 80 (setq n2 (concat n1 (car suffixes))) 81 (if (and (or (file-executable-p n2) 82 (and eshell-force-execution 83 (file-readable-p n2))) 84 (not (file-directory-p n2))) 85 (setq file n2 suffixes nil list nil)) 86 (setq suffixes (cdr suffixes))) 87 (setq list (cdr list))) 88 file))) 89 90(defcustom eshell-windows-shell-file 91 (if (eshell-under-windows-p) 92 (if (string-match "\\(\\`cmdproxy\\|sh\\)\\.\\(com\\|exe\\)" 93 shell-file-name) 94 (or (eshell-search-path "cmd.exe") 95 (eshell-search-path "command.com")) 96 shell-file-name)) 97 "*The name of the shell command to use for DOS/Windows batch files. 98This defaults to nil on non-Windows systems, where this variable is 99wholly ignored." 100 :type '(choice file (const nil)) 101 :group 'eshell-ext) 102 103(defsubst eshell-invoke-batch-file (&rest args) 104 "Invoke a .BAT or .CMD file on DOS/Windows systems." 105 ;; since CMD.EXE can't handle forward slashes in the initial 106 ;; argument... 107 (setcar args (subst-char-in-string ?/ ?\\ (car args))) 108 (throw 'eshell-replace-command 109 (eshell-parse-command eshell-windows-shell-file (cons "/c" args)))) 110 111(defcustom eshell-interpreter-alist 112 (if (eshell-under-windows-p) 113 '(("\\.\\(bat\\|cmd\\)\\'" . eshell-invoke-batch-file))) 114 "*An alist defining interpreter substitutions. 115Each member is a cons cell of the form: 116 117 (MATCH . INTERPRETER) 118 119MATCH should be a regexp, which is matched against the command name, 120or a function. If either returns a non-nil value, then INTERPRETER 121will be used for that command. 122 123If INTERPRETER is a string, it will be called as the command name, 124with the original command name passed as the first argument, with all 125subsequent arguments following. If INTERPRETER is a function, it will 126be called with all of those arguments. Note that interpreter 127functions should throw `eshell-replace-command' with the alternate 128command form, or they should return a value compatible with the 129possible return values of `eshell-external-command', which see." 130 :type '(repeat (cons (choice regexp (function :tag "Predicate")) 131 (choice string (function :tag "Interpreter")))) 132 :group 'eshell-ext) 133 134(defcustom eshell-alternate-command-hook nil 135 "*A hook run whenever external command lookup fails. 136If a functions wishes to provide an alternate command, they must throw 137it using the tag `eshell-replace-command'. This is done because the 138substituted command need not be external at all, and therefore must be 139passed up to a higher level for re-evaluation. 140 141Or, if the function returns a filename, that filename will be invoked 142with the current command arguments rather than the command specified 143by the user on the command line." 144 :type 'hook 145 :group 'eshell-ext) 146 147(defcustom eshell-command-interpreter-max-length 256 148 "*The maximum length of any command interpreter string, plus args." 149 :type 'integer 150 :group 'eshell-ext) 151 152(defcustom eshell-explicit-command-char ?* 153 "*If this char occurs before a command name, call it externally. 154That is, although `vi' may be an alias, `\vi' will always call the 155external version." 156 :type 'character 157 :group 'eshell-ext) 158 159;;; Functions: 160 161(defun eshell-ext-initialize () 162 "Initialize the external command handling code." 163 (add-hook 'eshell-named-command-hook 'eshell-explicit-command nil t)) 164 165(defun eshell-explicit-command (command args) 166 "If a command name begins with `*', call it externally always. 167This bypasses all Lisp functions and aliases." 168 (when (and (> (length command) 1) 169 (eq (aref command 0) eshell-explicit-command-char)) 170 (let ((cmd (eshell-search-path (substring command 1)))) 171 (if cmd 172 (or (eshell-external-command cmd args) 173 (error "%s: external command failed" cmd)) 174 (error "%s: external command not found" 175 (substring command 1)))))) 176 177(defun eshell-remote-command (handler command args) 178 "Insert output from a remote COMMAND, using ARGS. 179A remote command is something that executes on a different machine. 180An external command simply means external to Emacs. 181 182Note that this function is very crude at the moment. It gathers up 183all the output from the remote command, and sends it all at once, 184causing the user to wonder if anything's really going on..." 185 (let ((outbuf (generate-new-buffer " *eshell remote output*")) 186 (errbuf (generate-new-buffer " *eshell remote error*")) 187 (exitcode 1)) 188 (unwind-protect 189 (progn 190 (setq exitcode 191 (funcall handler 'shell-command 192 (mapconcat 'shell-quote-argument 193 (append (list command) args) " ") 194 outbuf errbuf)) 195 (eshell-print (save-excursion (set-buffer outbuf) 196 (buffer-string))) 197 (eshell-error (save-excursion (set-buffer errbuf) 198 (buffer-string)))) 199 (eshell-close-handles exitcode 'nil) 200 (kill-buffer outbuf) 201 (kill-buffer errbuf)))) 202 203(defun eshell-external-command (command args) 204 "Insert output from an external COMMAND, using ARGS." 205 (setq args (eshell-stringify-list (eshell-flatten-list args))) 206 (let ((handler 207 (unless (or (equal default-directory "/") 208 (and (eshell-under-windows-p) 209 (string-match "\\`[A-Za-z]:[/\\\\]\\'" 210 default-directory))) 211 (find-file-name-handler default-directory 212 'shell-command)))) 213 (if (and handler 214 (not (and (eshell-under-xemacs-p) 215 (eq handler 'dired-handler-fn)))) 216 (eshell-remote-command handler command args)) 217 (let ((interp (eshell-find-interpreter command))) 218 (assert interp) 219 (if (functionp (car interp)) 220 (apply (car interp) (append (cdr interp) args)) 221 (eshell-gather-process-output 222 (car interp) (append (cdr interp) args)))))) 223 224(defun eshell/addpath (&rest args) 225 "Add a set of paths to PATH." 226 (eshell-eval-using-options 227 "addpath" args 228 '((?b "begin" nil prepend "add path element at beginning") 229 (?h "help" nil nil "display this usage message") 230 :usage "[-b] PATH 231Adds the given PATH to $PATH.") 232 (if args 233 (progn 234 (if prepend 235 (setq args (nreverse args))) 236 (while args 237 (setenv "PATH" 238 (if prepend 239 (concat (car args) path-separator 240 (getenv "PATH")) 241 (concat (getenv "PATH") path-separator 242 (car args)))) 243 (setq args (cdr args)))) 244 (let ((paths (parse-colon-path (getenv "PATH")))) 245 (while paths 246 (eshell-printn (car paths)) 247 (setq paths (cdr paths))))))) 248 249(put 'eshell/addpath 'eshell-no-numeric-conversions t) 250 251(defun eshell-script-interpreter (file) 252 "Extract the script to run from FILE, if it has #!<interp> in it. 253Return nil, or a list of the form: 254 255 (INTERPRETER [ARGS] FILE)" 256 (let ((maxlen eshell-command-interpreter-max-length)) 257 (if (and (file-readable-p file) 258 (file-regular-p file)) 259 (with-temp-buffer 260 (insert-file-contents-literally file nil 0 maxlen) 261 (if (looking-at "#![ \t]*\\([^ \r\t\n]+\\)\\([ \t]+\\(.+\\)\\)?") 262 (if (match-string 3) 263 (list (match-string 1) 264 (match-string 3) 265 file) 266 (list (match-string 1) 267 file))))))) 268 269(defun eshell-find-interpreter (file &optional no-examine-p) 270 "Find the command interpreter with which to execute FILE. 271If NO-EXAMINE-P is non-nil, FILE will not be inspected for a script 272line of the form #!<interp>." 273 (let ((finterp 274 (catch 'found 275 (ignore 276 (eshell-for possible eshell-interpreter-alist 277 (cond 278 ((functionp (car possible)) 279 (and (funcall (car possible) file) 280 (throw 'found (cdr possible)))) 281 ((stringp (car possible)) 282 (and (string-match (car possible) file) 283 (throw 'found (cdr possible)))) 284 (t 285 (error "Invalid interpreter-alist test")))))))) 286 (if finterp ; first check 287 (list finterp file) 288 (let ((fullname (if (file-name-directory file) file 289 (eshell-search-path file))) 290 (suffixes eshell-binary-suffixes)) 291 (if (and fullname (not (or eshell-force-execution 292 (file-executable-p fullname)))) 293 (while suffixes 294 (let ((try (concat fullname (car suffixes)))) 295 (if (or (file-executable-p try) 296 (and eshell-force-execution 297 (file-readable-p try))) 298 (setq fullname try suffixes nil) 299 (setq suffixes (cdr suffixes)))))) 300 (cond ((not (and fullname (file-exists-p fullname))) 301 (let ((name (or fullname file))) 302 (unless (setq fullname 303 (run-hook-with-args-until-success 304 'eshell-alternate-command-hook file)) 305 (error "%s: command not found" name)))) 306 ((not (or eshell-force-execution 307 (file-executable-p fullname))) 308 (error "%s: Permission denied" fullname))) 309 (let (interp) 310 (unless no-examine-p 311 (setq interp (eshell-script-interpreter fullname)) 312 (if interp 313 (setq interp 314 (cons (car (eshell-find-interpreter (car interp) t)) 315 (cdr interp))))) 316 (or interp (list fullname))))))) 317 318;;; Code: 319 320;;; arch-tag: 178d4064-7e60-4745-b81f-bab5d8d7c40f 321;;; esh-ext.el ends here 322