-;; process command line arguments from within a suspended emacs job
-;; Copyright (C) 1988 Free Software Foundation, Inc.
+;;; resume.el --- process command line args from within a suspended Emacs job
-;; This file is not yet part of GNU Emacs, but soon will be.
+;; Copyright (C) 1992, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+
+;; Author: Joe Wells <jbw@bucsf.bu.edu>
+;; Adapted-By: ESR
+;; Keywords: processes
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs 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)
+;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
-;; but WITHOUT ANY WARRANTY. No author or distributor
-;; accepts responsibility to anyone for the consequences of using it
-;; or for whether it serves any particular purpose or works at all,
-;; unless he says so in writing. Refer to the GNU Emacs General Public
-;; License for full details.
-
-;; Everyone is granted permission to copy, modify and redistribute
-;; GNU Emacs, but only under the conditions described in the
-;; GNU Emacs General Public License. A copy of this license is
-;; supposed to have been given to you along with GNU Emacs so you
-;; can know your rights and responsibilities. It should be in a
-;; file named COPYING. Among other things, the copyright notice
-;; and this notice must be preserved on all copies.
-;;
-;; by Joe Wells
-;; jbw@bucsf.bu.edu
-;; joew@uswat.uswest.com (maybe, ... the mailer there sucks)
+;; 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.
+
+;;; Commentary:
+
+;; The purpose of this library is to handle command line arguments
+;; when you resume an existing Emacs job.
+
+;; In order to use it, you must put this code in your .emacs file.
+
+;; (add-hook 'suspend-hook 'resume-suspend-hook)
+;; (add-hook 'suspend-resume-hook 'resume-process-args)
+
+;; You can't get the benefit of this library by using the `emacs' command,
+;; since that always starts a new Emacs job. Instead you must use a
+;; command called `edit' which knows how to resume an existing Emacs job
+;; if you have one, or start a new Emacs job if you don't have one.
+
+;; To define the `edit' command, run the script etc/emacs.csh (if you use CSH),
+;; or etc/emacs.bash if you use BASH. You would normally do this in your
+;; login script.
;; Stephan Gildea suggested bug fix (gildea@bbn.com).
;; Ideas from Michael DeCorte and other people.
-;; For csh users, insert the following alias in your .cshrc file
-;; (after removing the leading double semicolons):
-;;
-;;# The following line could be just EMACS=emacs, but this depends on
-;;# your site.
-;;set EMACS=emacs
-;;set EMACS_PATTERN="^\[[0-9]\] . Stopped ............ $EMACS"
-;;alias emacs \
-;;' \\
-;; jobs >! /tmp/jobs$$ \\
-;; && grep "$EMACS_PATTERN" /tmp/jobs$$ >& /dev/null \\
-;; && echo `pwd` \!* >! ~/.emacs_args && eval "%$EMACS" \\
-;;|| test -S ~/.emacs_server && emacsclient \!* \\
-;;|| test "$?DISPLAY" = 1 && eval "\$EMACS -i \!* &" \\
-;;|| test "$?WINDOW_PARENT" = 1 && eval "emacstool -f emacstool-init \!* &" \\
-;;|| eval "\$EMACS -nw \!*"'
-;;
-;; The alias works as follows:
-;; 1. If there is a suspended emacs jobs that is a child of the
-;; current shell, place its arguments in the ~/.emacs_args file and
-;; resume it.
-;; 2. Else if the ~/.emacs_server socket has been created, presume an
-;; emacs server is running and attempt to connect to it. If no emacs
-;; server is listening on the socket, this will fail.
-;; 3. Else if the DISPLAY environment variable is set, presume we are
-;; running under X Windows and start a new X Gnu Emacs process in the
-;; background.
-;; 4. Else if the WINDOW_PARENT environment variable is set, presume we
-;; are running under Sunview and Suntools and start an emacstool
-;; process in the background.
-;; 5. Else start a regular emacs process.
-;;
-;; Notes:
-;; "test -S" checks if a unix domain socket by that name exists.
-;; The output of the "jobs" command is not piped directly into "grep"
-;; because that would run the "jobs" command in a subshell.
-;; Before resuming a suspended emacs, the current directory and all
-;; command line arguments are placed in a file.
-;; The command to run emacs is always preceded by a \ to prevent
-;; possible alias loops.
-;; The "-nw" switch in the last line is is undocumented, and it means
-;; no windowing system.
-\f
-(setq suspend-resume-hook 'resume-process-args)
-(setq suspend-hook 'resume-preparation)
-
-(defvar emacs-args-file "~/.emacs_args"
+;;; Code:
+
+(defvar resume-emacs-args-file (expand-file-name "~/.emacs_args")
"*This file is where arguments are placed for a suspended emacs job.")
-(defun resume-preparation ()
- (condition-case ()
- (delete-file emacs-args-file)
- (error nil)))
+(defvar resume-emacs-args-buffer " *Command Line Args*"
+ "Buffer that is used by resume-process-args.")
(defun resume-process-args ()
- "This should be called from inside of suspend-resume-hook.
-Grabs the contents of the file whose name is stored in
-emacs-args-file, and processes these arguments like command line options."
- (let ((resume-start-buffer (current-buffer))
- (resume-args-buffer (get-buffer-create " *Command Line Args*"))
- resume-args)
+ "Handler for command line args given when Emacs is resumed."
+ (let ((start-buffer (current-buffer))
+ (args-buffer (get-buffer-create resume-emacs-args-buffer))
+ length args
+ (command-line-default-directory default-directory))
(unwind-protect
(progn
- (set-buffer resume-args-buffer)
+ (set-buffer args-buffer)
(erase-buffer)
- ;; Get the contents of emacs-args-file, then delete the file.
+ ;; get the contents of resume-emacs-args-file
(condition-case ()
- (progn
- (insert-file-contents emacs-args-file)
- (delete-file emacs-args-file))
- ;; The file doesn't exist or we can't delete it, ergo no arguments.
- ;; (If we can't delete it now, we probably couldn't delete it
- ;; before suspending, and that implies it may be vestigial.)
- (file-error (erase-buffer)))
- ;; Get the arguments from the buffer.
- (goto-char (point-min))
- (while (progn (skip-chars-forward " \t\n") (not (eobp)))
- (setq resume-args
- (cons (buffer-substring (point)
- (progn
- (skip-chars-forward "^ \t\n")
- (point)))
- resume-args)))
- (cond (resume-args
- ;; Arguments are now in reverse order.
- (setq resume-args (nreverse resume-args))
- ;; The "first argument" is really a default directory to use
- ;; while processing the rest of the arguments.
- (setq default-directory (concat (car resume-args) "/"))
- ;; Actually process the arguments.
- (command-line-1 (cdr resume-args)))))
+ (let ((result (insert-file-contents resume-emacs-args-file)))
+ (setq length (car (cdr result))))
+ ;; the file doesn't exist, ergo no arguments
+ (file-error
+ (erase-buffer)
+ (setq length 0)))
+ (if (<= length 0)
+ (setq args nil)
+ ;; get the arguments from the buffer
+ (goto-char (point-min))
+ (while (not (eobp))
+ (skip-chars-forward " \t\n")
+ (let ((begin (point)))
+ (skip-chars-forward "^ \t\n")
+ (setq args (cons (buffer-substring begin (point)) args)))
+ (skip-chars-forward " \t\n"))
+ ;; arguments are now in reverse order
+ (setq args (nreverse args))
+ ;; make sure they're not read again
+ (erase-buffer))
+ (resume-write-buffer-to-file (current-buffer) resume-emacs-args-file)
+ ;; if nothing was in buffer, args will be null
+ (or (null args)
+ (setq command-line-default-directory
+ (file-name-as-directory (car args))
+ args (cdr args)))
+ ;; actually process the arguments
+ (command-line-1 args))
;; If the command line args don't result in a find-file, the
- ;; buffer will be left in resume-args-buffer. So we change back to the
+ ;; buffer will be left in args-buffer. So we change back to the
;; original buffer. The reason I don't just use
;; (let ((default-directory foo))
;; (command-line-1 args))
;; in the context of the original buffer is because let does not
;; work properly with buffer-local variables.
- (if (eq (current-buffer) resume-args-buffer)
- (set-buffer resume-start-buffer)))))
+ (if (eq (current-buffer) args-buffer)
+ (set-buffer start-buffer)))))
+
+;;;###autoload
+(defun resume-suspend-hook ()
+ "Clear out the file used for transmitting args when Emacs resumes."
+ (save-excursion
+ (set-buffer (get-buffer-create resume-emacs-args-buffer))
+ (erase-buffer)
+ (resume-write-buffer-to-file (current-buffer) resume-emacs-args-file)))
+
+(defun resume-write-buffer-to-file (buffer file)
+ "Writes the contents of BUFFER into FILE, if permissions allow."
+ (if (not (file-writable-p file))
+ (error "No permission to write file %s" file))
+ (save-excursion
+ (set-buffer buffer)
+ (clear-visited-file-modtime)
+ (save-restriction
+ (widen)
+ (write-region (point-min) (point-max) file nil 'quiet))
+ (set-buffer-modified-p nil)))
+
+(provide 'resume)
+
+;;; arch-tag: c90b2761-4803-4e58-a0ae-c4721368b628
+;;; resume.el ends here