code.delx.au - gnu-emacs/blob - 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,
   4 ;;   2005, 2006, 2007, 2008 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 (defgroup eshell-banner nil
  50   "This sample module displays a welcome banner at login.
  51 It exists so that others wishing to create their own Eshell extension
  52 modules may have a simple template to begin with."
  53   :tag "Login banner"
  54   ;; :link '(info-link "(eshell)Login banner")
  55   :group 'eshell-module)
  56
  57 ;;; User Variables:
  58
  59 (defcustom eshell-banner-message "Welcome to the Emacs shell\n\n"
  60   "*The banner message to be displayed when Eshell is loaded.
  61 This can be any sexp, and should end with at least two newlines."
  62   :type 'sexp
  63   :group 'eshell-banner)
  64
  65 (put 'eshell-banner-message 'risky-local-variable t)
  66
  67 (defcustom eshell-banner-load-hook '(eshell-banner-initialize)
  68   "*A list of functions to run when `eshell-banner' is loaded."
  69   :type 'hook
  70   :group 'eshell-banner)
  71
  72 (defun eshell-banner-initialize ()
  73   "Output a welcome banner on initialization."
  74   ;; it's important to use `eshell-interactive-print' rather than
  75   ;; `insert', because `insert' doesn't know how to interact with the
  76   ;; I/O code used by Eshell
  77   (unless eshell-non-interactive-p
  78     (assert eshell-mode)
  79     (assert eshell-banner-message)
  80     (let ((msg (eval eshell-banner-message)))
  81       (assert msg)
  82       (eshell-interactive-print msg))))
  83
  84 (eshell-deftest banner banner-displayed
  85   "Startup banner is displayed at point-min"
  86   (assert eshell-banner-message)
  87   (let ((msg (eval eshell-banner-message)))
  88     (assert msg)
  89     (goto-char (point-min))
  90     (looking-at msg)))
  91
  92 (provide 'em-banner)
  93
  94 ;; arch-tag: e738b4ef-8671-42ae-a757-291779b92491
  95 ;;; em-banner.el ends here