+;;; openwith.el --- Open files with external programs
+;; Copyright (C) 2007 Markus Triska
+;; Author: Markus Triska <email@example.com>
+;; Keywords: files, processes
+;; This file is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; This file is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING. If not, write to
+;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
+;; This lets you associate external applications with files so that
+;; you can open them via C-x C-f, with RET in dired, etc.
+;; Copy openwith.el to your load-path and add to your .emacs:
+;; To customize associations etc., use:
+;; M-x customize-group RET openwith RET
+(defconst openwith-version "0.8f")
+ "Associate external applications with file name patterns."
+ '(("\\.pdf\\'" "acroread" (file))
+ ("\\.mp3\\'" "xmms" (file))
+ ("\\.\\(?:mpe?g\\|avi\\|wmv\\)\\'" "mplayer" ("-idx" file))
+ ("\\.\\(?:jp?g\\|png\\)\\'" "display" (file)))
+ "Associations of file patterns to external programs.
+File pattern is a regular expression describing the files to
+associate with a program. The program arguments are a list of
+strings and symbols and are passed to the program on invocation,
+where the symbol 'file' is replaced by the file to be opened."
+ :type '(repeat (list (regexp :tag "Files")
+ (string :tag "Program")
+ (sexp :tag "Parameters"))))
+(defcustom openwith-confirm-invocation nil
+ "Ask for confirmation before invoking external programs."
+(defun openwith-file-handler (operation &rest args)
+ "Open file with external program, if an association is configured."
+ (when (and openwith-mode (not (buffer-modified-p)) (zerop (buffer-size)))
+ (let ((assocs openwith-associations)
+ ;; do not use `dolist' here, since some packages (like cl)
+ ;; temporarily unbind it
+ (when (save-match-data (string-match (car oa) file))
+ (let ((params (mapcar (lambda (x) (if (eq x 'file) file x))
+ (when (or (not openwith-confirm-invocation)
+ (y-or-n-p (format "%s %s? " (cadr oa)
+ (mapconcat #'identity params " "))))
+ (apply #'start-process "openwith-process" nil (cadr oa) params)
+ ;; inhibit further actions
+ (error "Opened %s in external program"
+ (file-name-nondirectory file))))))))
+ ;; when no association was found, relay the operation to other handlers
+ (let ((inhibit-file-name-handlers
+ (cons 'openwith-file-handler
+ (and (eq inhibit-file-name-operation operation)
+ (inhibit-file-name-operation operation))
+ (apply operation args)))
+ "Automatically open files with external programs."
+ ;; register `openwith-file-handler' for all files
+ (put 'openwith-file-handler 'safe-magic t)
+ (put 'openwith-file-handler 'operations '(insert-file-contents))
+ (add-to-list 'file-name-handler-alist '("" . openwith-file-handler)))
+ (setq file-name-handler-alist
+ (delete '("" . openwith-file-handler) file-name-handler-alist))))
+;;; openwith.el ends here