| 1 | ;;; resume.el --- process command line args from within a suspended Emacs job |
| 2 | |
| 3 | ;; Copyright (C) 1992 Free Software Foundation, Inc. |
| 4 | |
| 5 | ;; Author: Joe Wells <jbw@bucsf.bu.edu> |
| 6 | ;; Adapted-By: ESR |
| 7 | ;; Keywords: processes |
| 8 | |
| 9 | ;; This file is part of GNU Emacs. |
| 10 | |
| 11 | ;; GNU Emacs is free software; you can redistribute it and/or modify |
| 12 | ;; it under the terms of the GNU General Public License as published by |
| 13 | ;; the Free Software Foundation; either version 2, or (at your option) |
| 14 | ;; any later version. |
| 15 | |
| 16 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| 17 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | ;; GNU General Public License for more details. |
| 20 | |
| 21 | ;; You should have received a copy of the GNU General Public License |
| 22 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
| 23 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| 24 | ;; Boston, MA 02111-1307, USA. |
| 25 | |
| 26 | ;;; Commentary: |
| 27 | |
| 28 | ;; The purpose of this library is to handle command line arguments |
| 29 | ;; when you resume an existing Emacs job. |
| 30 | |
| 31 | ;; In order to use it, you must put this code in your .emacs file. |
| 32 | |
| 33 | ;; (add-hook 'suspend-hook 'resume-suspend-hook) |
| 34 | ;; (add-hook 'suspend-resume-hook 'resume-process-args) |
| 35 | |
| 36 | ;; You can't get the benefit of this library by using the `emacs' command, |
| 37 | ;; since that always starts a new Emacs job. Instead you must use a |
| 38 | ;; command called `edit' which knows how to resume an existing Emacs job |
| 39 | ;; if you have one, or start a new Emacs job if you don't have one. |
| 40 | |
| 41 | ;; To define the `edit' command, run the script etc/emacs.csh (if you use CSH), |
| 42 | ;; or etc/emacs.bash if you use BASH. You would normally do this in your |
| 43 | ;; login script. |
| 44 | |
| 45 | ;; Stephan Gildea suggested bug fix (gildea@bbn.com). |
| 46 | ;; Ideas from Michael DeCorte and other people. |
| 47 | |
| 48 | ;;; Code: |
| 49 | |
| 50 | (defvar resume-emacs-args-file (expand-file-name "~/.emacs_args") |
| 51 | "*This file is where arguments are placed for a suspended emacs job.") |
| 52 | |
| 53 | (defvar resume-emacs-args-buffer " *Command Line Args*" |
| 54 | "Buffer that is used by resume-process-args.") |
| 55 | |
| 56 | (defun resume-process-args () |
| 57 | "Handler for command line args given when Emacs is resumed." |
| 58 | (let ((start-buffer (current-buffer)) |
| 59 | (args-buffer (get-buffer-create resume-emacs-args-buffer)) |
| 60 | length args |
| 61 | (command-line-default-directory default-directory)) |
| 62 | (unwind-protect |
| 63 | (progn |
| 64 | (set-buffer args-buffer) |
| 65 | (erase-buffer) |
| 66 | ;; get the contents of resume-emacs-args-file |
| 67 | (condition-case () |
| 68 | (let ((result (insert-file-contents resume-emacs-args-file))) |
| 69 | (setq length (car (cdr result)))) |
| 70 | ;; the file doesn't exist, ergo no arguments |
| 71 | (file-error |
| 72 | (erase-buffer) |
| 73 | (setq length 0))) |
| 74 | (if (<= length 0) |
| 75 | (setq args nil) |
| 76 | ;; get the arguments from the buffer |
| 77 | (goto-char (point-min)) |
| 78 | (while (not (eobp)) |
| 79 | (skip-chars-forward " \t\n") |
| 80 | (let ((begin (point))) |
| 81 | (skip-chars-forward "^ \t\n") |
| 82 | (setq args (cons (buffer-substring begin (point)) args))) |
| 83 | (skip-chars-forward " \t\n")) |
| 84 | ;; arguments are now in reverse order |
| 85 | (setq args (nreverse args)) |
| 86 | ;; make sure they're not read again |
| 87 | (erase-buffer)) |
| 88 | (resume-write-buffer-to-file (current-buffer) resume-emacs-args-file) |
| 89 | ;; if nothing was in buffer, args will be null |
| 90 | (or (null args) |
| 91 | (setq command-line-default-directory |
| 92 | (file-name-as-directory (car args)) |
| 93 | args (cdr args))) |
| 94 | ;; actually process the arguments |
| 95 | (command-line-1 args)) |
| 96 | ;; If the command line args don't result in a find-file, the |
| 97 | ;; buffer will be left in args-buffer. So we change back to the |
| 98 | ;; original buffer. The reason I don't just use |
| 99 | ;; (let ((default-directory foo)) |
| 100 | ;; (command-line-1 args)) |
| 101 | ;; in the context of the original buffer is because let does not |
| 102 | ;; work properly with buffer-local variables. |
| 103 | (if (eq (current-buffer) args-buffer) |
| 104 | (set-buffer start-buffer))))) |
| 105 | |
| 106 | ;;;###autoload |
| 107 | (defun resume-suspend-hook () |
| 108 | "Clear out the file used for transmitting args when Emacs resumes." |
| 109 | (save-excursion |
| 110 | (set-buffer (get-buffer-create resume-emacs-args-buffer)) |
| 111 | (erase-buffer) |
| 112 | (resume-write-buffer-to-file (current-buffer) resume-emacs-args-file))) |
| 113 | |
| 114 | (defun resume-write-buffer-to-file (buffer file) |
| 115 | "Writes the contents of BUFFER into FILE, if permissions allow." |
| 116 | (if (not (file-writable-p file)) |
| 117 | (error "No permission to write file %s" file)) |
| 118 | (save-excursion |
| 119 | (set-buffer buffer) |
| 120 | (clear-visited-file-modtime) |
| 121 | (save-restriction |
| 122 | (widen) |
| 123 | (write-region (point-min) (point-max) file nil 'quiet)) |
| 124 | (set-buffer-modified-p nil))) |
| 125 | |
| 126 | (provide 'resume) |
| 127 | |
| 128 | ;;; resume.el ends here |