lisp/eshell/em-banner.el

   1 ;;; em-banner --- sample module that displays a login banner
   2
   3 ;; Copyright (C) 1999, 2000 Free Sofware Foundation
   4
   5 ;; This file is part of GNU Emacs.
   6
   7 ;; GNU Emacs is free software; you can redistribute it and/or modify
   8 ;; it under the terms of the GNU General Public License as published by
   9 ;; the Free Software Foundation; either version 2, or (at your option)
  10 ;; any later version.
  11
  12 ;; GNU Emacs is distributed in the hope that it will be useful,
  13 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;; GNU General Public License for more details.
  16
  17 ;; You should have received a copy of the GNU General Public License
  18 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  19 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 ;; Boston, MA 02111-1307, USA.
  21
  22 (provide 'em-banner)
  23
  24 (eval-when-compile (require 'esh-maint))
  25
  26 (defgroup eshell-banner nil
  27   "This sample module displays a welcome banner at login.
  28 It exists so that others wishing to create their own Eshell extension
  29 modules may have a simple template to begin with."
  30   :tag "Login banner"
  31   :link '(info-link "(eshell.info)Login banner")
  32   :group 'eshell-module)
  33
  34 ;;; Commentary:
  35
  36 ;; There is nothing to be done or configured in order to use this
  37 ;; module, other than to select it by customizing the variable
  38 ;; `eshell-modules-list'.  It will then display a version information
  39 ;; message whenever Eshell is loaded.
  40 ;;
  41 ;; This code is only an example of a how to write a well-formed
  42 ;; extension module for Eshell.  The better way to display login text
  43 ;; is to use the `eshell-script' module, and to echo the desired
  44 ;; strings from the user's `eshell-login-script' file.
  45 ;;
  46 ;; There is one configuration variable, which demonstrates how to
  47 ;; properly define a customization variable in an extension module.
  48 ;; In this case, it allows the user to change the string which
  49 ;; displays at login time.
  50
  51 ;;; User Variables:
  52
  53 (defcustom eshell-banner-message "Welcome to the Emacs shell\n\n"
  54   "*The banner message to be displayed when Eshell is loaded.
  55 This can be any sexp, and should end with at least two newlines."
  56   :type 'sexp
  57   :group 'eshell-banner)
  58
  59 (put 'eshell-banner-message 'risky-local-variable t)
  60
  61 ;;; Code:
  62
  63 (require 'esh-util)
  64
  65 (defcustom eshell-banner-load-hook '(eshell-banner-initialize)
  66   "*A list of functions to run when `eshell-banner' is loaded."
  67   :type 'hook
  68   :group 'eshell-banner)
  69
  70 (defun eshell-banner-initialize ()
  71   "Output a welcome banner on initialization."
  72   ;; it's important to use `eshell-interactive-print' rather than
  73   ;; `insert', because `insert' doesn't know how to interact with the
  74   ;; I/O code used by Eshell
  75   (unless eshell-non-interactive-p
  76     (assert eshell-mode)
  77     (assert eshell-banner-message)
  78     (let ((msg (eval eshell-banner-message)))
  79       (assert msg)
  80       (eshell-interactive-print msg))))
  81
  82 (eshell-deftest banner banner-displayed
  83   "Startup banner is displayed at point-min"
  84   (assert eshell-banner-message)
  85   (let ((msg (eval eshell-banner-message)))
  86     (assert msg)
  87     (goto-char (point-min))
  88     (looking-at msg)))
  89
  90 ;;; em-banner.el ends here