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Diffstat (limited to 'restart-emacs.el')
| -rw-r--r-- | restart-emacs.el | 159 |
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diff --git a/restart-emacs.el b/restart-emacs.el new file mode 100644 index 0000000..c5e4f8d --- /dev/null +++ b/restart-emacs.el @@ -0,0 +1,159 @@ +;;; restart-emacs.el --- Restart emacs from within emacs -*- lexical-binding: t; -*- + +;; Copyright (C) 2015 Iqbal Ansari + +;; Author: Iqbal Ansari <iqbalansari02@yahoo.com> +;; Keywords: convenience +;; URL: https://github.com/iqbalansari/restart-emacs +;; Version: 0.1.1 + +;; This program 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. + +;; This program 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 this program. If not, see <http://www.gnu.org/licenses/>. + +;;; Commentary: + +;; This package provides a simple command to restart Emacs from within Emacs + + + +;;; Code: + +;; Making the byte compiler happy +(declare-function w32-shell-execute "w32fns.c") + + + +;; Compatibility functions + +(defun restart-emacs--string-join (strings &optional separator) + "Join all STRINGS using SEPARATOR. + +This function is available on Emacs v24.4 and higher, it has been +backported here for compatibility with older Emacsen." + (if (fboundp 'string-join) + (apply #'string-join (list strings separator)) + (mapconcat 'identity strings separator))) + +(defun restart-emacs--user-error (format &rest args) + "Signal a `user-error' if available otherwise signal a generic `error'. + +FORMAT and ARGS correspond to STRING and OBJECTS arguments to `format'." + (if (fboundp 'user-error) + (apply #'user-error format args) + (apply #'error format args))) + + + +;; Core functions + +(defvar restart-emacs--args nil + "The arguments with which to restart Emacs is bound dynamically.") + +(defun restart-emacs--get-emacs-binary () + "Get absolute path to binary of currently running Emacs." + (expand-file-name invocation-name invocation-directory)) + +(defun restart-emacs--start-gui-using-sh (&optional args) + "Start GUI version of Emacs using sh. + +ARGS is the list arguments with which Emacs should be started" + (call-process "sh" nil + 0 nil + "-c" (format "%s %s &" + (shell-quote-argument (restart-emacs--get-emacs-binary)) + (restart-emacs--string-join (mapcar #'shell-quote-argument + args) + " ")))) + +(defun restart-emacs--start-gui-on-windows (&optional args) + "Start GUI version of Emacs on windows. + +ARGS is the list arguments with which Emacs should be started" + (w32-shell-execute "open" (restart-emacs--get-emacs-binary) args)) + +(defun restart-emacs--start-emacs-in-terminal (&optional args) + "Start Emacs in current terminal. + +ARGS is the list arguments with which Emacs should be started. This requires a +shell with `fg' command and `;' construct. This has been tested to work with +sh, bash, zsh, fish, csh and tcsh shells" + (suspend-emacs (format "fg ; %s %s -nw" + (shell-quote-argument (restart-emacs--get-emacs-binary)) + (restart-emacs--string-join (mapcar #'shell-quote-argument + args) + " ")))) + +(defun restart-emacs--ensure-can-restart () + "Ensure we can restart Emacs on current platform." + (when (and (not (display-graphic-p)) + (memq system-type '(windows-nt ms-dos))) + (restart-emacs--user-error (format "Cannot restart emacs running in terminal on system of type `%s'" system-type)))) + +(defun restart-emacs--launch-other-emacs () + "Launch another Emacs session according to current platform." + (apply (if (display-graphic-p) + (if (memq system-type '(windows-nt ms-dos)) + #'restart-emacs--start-gui-on-windows + #'restart-emacs--start-gui-using-sh) + (if (memq system-type '(windows-nt ms-dos)) + ;; This should not happen since we check this before triggering a restart + (restart-emacs--user-error "Cannot restart Emacs running in a windows terminal") + #'restart-emacs--start-emacs-in-terminal)) + ;; Since this function is called in `kill-emacs-hook' it cannot accept + ;; direct arguments the arguments are let-bound instead + (list restart-emacs--args))) + +(defun restart-emacs--translate-prefix-to-args (prefix) + "Translate the given PREFIX to arguments to be passed to Emacs. + +It does the following translation + `C-u' => --debug-init + `C-u' `C-u' => -Q +`C-u' `C-u' `C-u' => Reads the argument from the user in raw form" + (cond ((equal prefix '(4)) '("--debug-init")) + ((equal prefix '(16)) '("-Q")) + ((equal prefix '(64)) (split-string (read-string "Arguments to start Emacs with (separated by space): ") + " ")))) + + + +;; User interface + +;;;###autoload +(defun restart-emacs (&optional args) + "Restart Emacs. + +When called interactively ARGS is interpreted as follows + +- with a single `universal-argument' (`C-u') Emacs is restarted + with `--debug-init' flag +- with two `universal-argument' (`C-u') Emacs is restarted with + `-Q' flag +- with three `universal-argument' (`C-u') the user prompted for + the arguments + +When called non-interactively ARGS should be a list of arguments +with which Emacs should be restarted." + (interactive "P") + ;; Do not trigger a restart unless we are sure, we can restart emacs + (restart-emacs--ensure-can-restart) + ;; We need the new emacs to be spawned after all kill-emacs-hooks + ;; have been processed and there is nothing interesting left + (let ((kill-emacs-hook (append kill-emacs-hook (list #'restart-emacs--launch-other-emacs))) + (restart-emacs--args (if (called-interactively-p 'any) + (restart-emacs--translate-prefix-to-args args) + args))) + (save-buffers-kill-emacs))) + +(provide 'restart-emacs) +;;; restart-emacs.el ends here |