1;;; resume.el --- process command line args from within a suspended Emacs job 2 3;; Copyright (C) 1992, 2001, 2002, 2003, 2004, 2005, 4;; 2006, 2007 Free Software Foundation, Inc. 5 6;; Author: Joe Wells <jbw@bucsf.bu.edu> 7;; Adapted-By: ESR 8;; Keywords: processes 9 10;; This file is part of GNU Emacs. 11 12;; GNU Emacs is free software; you can redistribute it and/or modify 13;; it under the terms of the GNU General Public License as published by 14;; the Free Software Foundation; either version 2, or (at your option) 15;; any later version. 16 17;; GNU Emacs is distributed in the hope that it will be useful, 18;; but WITHOUT ANY WARRANTY; without even the implied warranty of 19;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20;; GNU General Public License for more details. 21 22;; You should have received a copy of the GNU General Public License 23;; along with GNU Emacs; see the file COPYING. If not, write to the 24;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 25;; Boston, MA 02110-1301, USA. 26 27;;; Commentary: 28 29;; The purpose of this library is to handle command line arguments 30;; when you resume an existing Emacs job. 31 32;; In order to use it, you must put this code in your .emacs file. 33 34;; (add-hook 'suspend-hook 'resume-suspend-hook) 35;; (add-hook 'suspend-resume-hook 'resume-process-args) 36 37;; You can't get the benefit of this library by using the `emacs' command, 38;; since that always starts a new Emacs job. Instead you must use a 39;; command called `edit' which knows how to resume an existing Emacs job 40;; if you have one, or start a new Emacs job if you don't have one. 41 42;; To define the `edit' command, run the script etc/emacs.csh (if you use CSH), 43;; or etc/emacs.bash if you use BASH. You would normally do this in your 44;; login script. 45 46;; Stephan Gildea suggested bug fix (gildea@bbn.com). 47;; Ideas from Michael DeCorte and other people. 48 49;;; Code: 50 51(defvar resume-emacs-args-file (expand-file-name "~/.emacs_args") 52 "*This file is where arguments are placed for a suspended Emacs job.") 53 54(defvar resume-emacs-args-buffer " *Command Line Args*" 55 "Buffer that is used by `resume-process-args'.") 56 57(defun resume-process-args () 58 "Handler for command line args given when Emacs is resumed." 59 (let ((start-buffer (current-buffer)) 60 (args-buffer (get-buffer-create resume-emacs-args-buffer)) 61 length args 62 (command-line-default-directory default-directory)) 63 (unwind-protect 64 (progn 65 (set-buffer args-buffer) 66 (erase-buffer) 67 ;; get the contents of resume-emacs-args-file 68 (condition-case () 69 (let ((result (insert-file-contents resume-emacs-args-file))) 70 (setq length (car (cdr result)))) 71 ;; the file doesn't exist, ergo no arguments 72 (file-error 73 (erase-buffer) 74 (setq length 0))) 75 (if (<= length 0) 76 (setq args nil) 77 ;; get the arguments from the buffer 78 (goto-char (point-min)) 79 (while (not (eobp)) 80 (skip-chars-forward " \t\n") 81 (let ((begin (point))) 82 (skip-chars-forward "^ \t\n") 83 (setq args (cons (buffer-substring begin (point)) args))) 84 (skip-chars-forward " \t\n")) 85 ;; arguments are now in reverse order 86 (setq args (nreverse args)) 87 ;; make sure they're not read again 88 (erase-buffer)) 89 (resume-write-buffer-to-file (current-buffer) resume-emacs-args-file) 90 ;; if nothing was in buffer, args will be null 91 (or (null args) 92 (setq command-line-default-directory 93 (file-name-as-directory (car args)) 94 args (cdr args))) 95 ;; actually process the arguments 96 (command-line-1 args)) 97 ;; If the command line args don't result in a find-file, the 98 ;; buffer will be left in args-buffer. So we change back to the 99 ;; original buffer. The reason I don't just use 100 ;; (let ((default-directory foo)) 101 ;; (command-line-1 args)) 102 ;; in the context of the original buffer is because let does not 103 ;; work properly with buffer-local variables. 104 (if (eq (current-buffer) args-buffer) 105 (set-buffer start-buffer))))) 106 107;;;###autoload 108(defun resume-suspend-hook () 109 "Clear out the file used for transmitting args when Emacs resumes." 110 (save-excursion 111 (set-buffer (get-buffer-create resume-emacs-args-buffer)) 112 (erase-buffer) 113 (resume-write-buffer-to-file (current-buffer) resume-emacs-args-file))) 114 115(defun resume-write-buffer-to-file (buffer file) 116 "Writes the contents of BUFFER into FILE, if permissions allow." 117 (if (not (file-writable-p file)) 118 (error "No permission to write file %s" file)) 119 (save-excursion 120 (set-buffer buffer) 121 (clear-visited-file-modtime) 122 (save-restriction 123 (widen) 124 (write-region (point-min) (point-max) file nil 'quiet)) 125 (set-buffer-modified-p nil))) 126 127(provide 'resume) 128 129;;; arch-tag: c90b2761-4803-4e58-a0ae-c4721368b628 130;;; resume.el ends here 131