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, or (at your option)
  13 ;; 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; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23 ;; Boston, MA 02110-1301, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; There is nothing to be done or configured in order to use this
  28 ;; module, other than to select it by customizing the variable
  29 ;; `eshell-modules-list'.  It will then display a version information
  30 ;; message whenever Eshell is loaded.
  31 ;;
  32 ;; This code is only an example of a how to write a well-formed
  33 ;; extension module for Eshell.  The better way to display login text
  34 ;; is to use the `eshell-script' module, and to echo the desired
  35 ;; strings from the user's `eshell-login-script' file.
  36 ;;
  37 ;; There is one configuration variable, which demonstrates how to
  38 ;; properly define a customization variable in an extension module.
  39 ;; In this case, it allows the user to change the string which
  40 ;; displays at login time.
  41
  42 ;;; Code:
  43
  44 (eval-when-compile
  45   (require 'cl)
  46   (require 'esh-mode)
  47   (require 'eshell))
  48
  49 (require 'esh-util)
  50
  51 (defgroup eshell-banner nil
  52   "This sample module displays a welcome banner at login.
  53 It exists so that others wishing to create their own Eshell extension
  54 modules may have a simple template to begin with."
  55   :tag "Login banner"
  56   ;; :link '(info-link "(eshell)Login banner")
  57   :group 'eshell-module)
  58
  59 ;;; User Variables:
  60
  61 (defcustom eshell-banner-message "Welcome to the Emacs shell\n\n"
  62   "*The banner message to be displayed when Eshell is loaded.
  63 This can be any sexp, and should end with at least two newlines."
  64   :type 'sexp
  65   :group 'eshell-banner)
  66
  67 (put 'eshell-banner-message 'risky-local-variable t)
  68
  69 (defcustom eshell-banner-load-hook '(eshell-banner-initialize)
  70   "*A list of functions to run when `eshell-banner' is loaded."
  71   :type 'hook
  72   :group 'eshell-banner)
  73
  74 (defun eshell-banner-initialize ()
  75   "Output a welcome banner on initialization."
  76   ;; it's important to use `eshell-interactive-print' rather than
  77   ;; `insert', because `insert' doesn't know how to interact with the
  78   ;; I/O code used by Eshell
  79   (unless eshell-non-interactive-p
  80     (assert eshell-mode)
  81     (assert eshell-banner-message)
  82     (let ((msg (eval eshell-banner-message)))
  83       (assert msg)
  84       (eshell-interactive-print msg))))
  85
  86 (eshell-deftest banner banner-displayed
  87   "Startup banner is displayed at point-min"
  88   (assert eshell-banner-message)
  89   (let ((msg (eval eshell-banner-message)))
  90     (assert msg)
  91     (goto-char (point-min))
  92     (looking-at msg)))
  93
  94 (provide 'em-banner)
  95
  96 ;; arch-tag: e738b4ef-8671-42ae-a757-291779b92491
  97 ;;; em-banner.el ends here