lisp/eshell/em-banner.el

   1 ;;; em-banner.el --- sample module that displays a login banner
   2
   3 ;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
   4 ;;   2008, 2009, 2010, 2011  Free Software Foundation, Inc.
   5
   6 ;; Author: John Wiegley <johnw@gnu.org>
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;; There is nothing to be done or configured in order to use this
  26 ;; module, other than to select it by customizing the variable
  27 ;; `eshell-modules-list'.  It will then display a version information
  28 ;; message whenever Eshell is loaded.
  29 ;;
  30 ;; This code is only an example of a how to write a well-formed
  31 ;; extension module for Eshell.  The better way to display login text
  32 ;; is to use the `eshell-script' module, and to echo the desired
  33 ;; strings from the user's `eshell-login-script' file.
  34 ;;
  35 ;; There is one configuration variable, which demonstrates how to
  36 ;; properly define a customization variable in an extension module.
  37 ;; In this case, it allows the user to change the string which
  38 ;; displays at login time.
  39
  40 ;;; Code:
  41
  42 (eval-when-compile
  43   (require 'cl)
  44   (require 'esh-mode)
  45   (require 'eshell))
  46
  47 (require 'esh-util)
  48
  49 ;;;###autoload
  50 (eshell-defgroup eshell-banner nil
  51   "This sample module displays a welcome banner at login.
  52 It exists so that others wishing to create their own Eshell extension
  53 modules may have a simple template to begin with."
  54   :tag "Login banner"
  55   ;; :link '(info-link "(eshell)Login banner")
  56   :group 'eshell-module)
  57
  58 ;;; User Variables:
  59
  60 (defcustom eshell-banner-message "Welcome to the Emacs shell\n\n"
  61   "The banner message to be displayed when Eshell is loaded.
  62 This can be any sexp, and should end with at least two newlines."
  63   :type 'sexp
  64   :group 'eshell-banner)
  65
  66 (put 'eshell-banner-message 'risky-local-variable t)
  67
  68 (defcustom eshell-banner-load-hook '(eshell-banner-initialize)
  69   "A list of functions to run when `eshell-banner' is loaded."
  70   :type 'hook
  71   :group 'eshell-banner)
  72
  73 (defun eshell-banner-initialize ()
  74   "Output a welcome banner on initialization."
  75   ;; it's important to use `eshell-interactive-print' rather than
  76   ;; `insert', because `insert' doesn't know how to interact with the
  77   ;; I/O code used by Eshell
  78   (unless eshell-non-interactive-p
  79     (assert eshell-mode)
  80     (assert eshell-banner-message)
  81     (let ((msg (eval eshell-banner-message)))
  82       (assert msg)
  83       (eshell-interactive-print msg))))
  84
  85 (eshell-deftest banner banner-displayed
  86   "Startup banner is displayed at point-min"
  87   (assert eshell-banner-message)
  88   (let ((msg (eval eshell-banner-message)))
  89     (assert msg)
  90     (goto-char (point-min))
  91     (looking-at msg)))
  92
  93 (provide 'em-banner)
  94
  95 ;; Local Variables:
  96 ;; generated-autoload-file: "esh-groups.el"
  97 ;; End:
  98
  99 ;;; em-banner.el ends here