1
0
mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-20 10:23:57 +00:00
emacs/lisp/obsolete/resume.el
2013-01-01 09:11:05 +00:00

126 lines
4.5 KiB
EmacsLisp

;;; resume.el --- process command line args from within a suspended Emacs job
;; Copyright (C) 1992, 2001-2013 Free Software Foundation, Inc.
;; Author: Joe Wells <jbw@bucsf.bu.edu>
;; Adapted-By: ESR
;; Keywords: processes
;; Obsolete-since: 23.1
;; 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 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs 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. If not, see <http://www.gnu.org/licenses/>.
;;; 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.
;;; Code:
(defvar resume-emacs-args-file (expand-file-name "~/.emacs_args")
"This file is where arguments are placed for a suspended Emacs job.")
(defvar resume-emacs-args-buffer " *Command Line Args*"
"Buffer that is used by `resume-process-args'.")
(defun resume-process-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 args-buffer)
(erase-buffer)
;; get the contents of resume-emacs-args-file
(condition-case ()
(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 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) args-buffer)
(set-buffer start-buffer)))))
;;;###autoload
(defun resume-suspend-hook ()
"Clear out the file used for transmitting args when Emacs resumes."
(with-current-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))
(with-current-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)
;;; resume.el ends here