lisp/paths.el

   1 ;;; paths.el --- define pathnames for use by various Emacs commands
   2
   3 ;; Copyright (C) 1986, 1988, 1994, 1999-2012 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: internal
   7 ;; Package: emacs
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; These are default settings for names of certain files and directories
  27 ;; that Emacs needs to refer to from time to time.
  28
  29 ;; If these settings are not right, override them with `setq'
  30 ;; in site-init.el.  Do not change this file.
  31
  32 ;;; Code:
  33
  34 ;; This is a defcustom largely so that we can get the benefit
  35 ;; of custom-initialize-delay.  Perhaps it would work to make it a
  36 ;; defvar and explicitly give it a standard-value property, and
  37 ;; call custom-initialize-delay on it.
  38 (defcustom Info-default-directory-list
  39   (let* ((config-dir
  40           (file-name-as-directory
  41            ;; Self-contained NS build with info/ in the app-bundle.
  42            (or (and (featurep 'ns)
  43                     (let ((dir (expand-file-name "../info" data-directory)))
  44                       (if (file-directory-p dir) dir)))
  45                configure-info-directory)))
  46          (prefixes
  47           ;; Directory trees in which to look for info subdirectories
  48           (prune-directory-list '("/usr/local/" "/usr/" "/opt/" "/")))
  49          (suffixes
  50           ;; Subdirectories in each directory tree that may contain info
  51           ;; directories.  Most of these are rather outdated.
  52           ;; It ought to be fine to stop checking the "emacs" ones now,
  53           ;; since this is Emacs and we have not installed info files
  54           ;; into such directories for a looong time...
  55           '("share/" "" "gnu/" "gnu/lib/" "gnu/lib/emacs/"
  56             "emacs/" "lib/" "lib/emacs/"))
  57          (standard-info-dirs
  58           (apply #'nconc
  59                  (mapcar (lambda (pfx)
  60                            (let ((dirs
  61                                   (mapcar (lambda (sfx)
  62                                             (concat pfx sfx "info/"))
  63                                           suffixes)))
  64                              (prune-directory-list dirs)))
  65                          prefixes)))
  66          ;; If $(prefix)/share/info is not one of the standard info
  67          ;; directories, they are probably installing an experimental
  68          ;; version of Emacs, so make sure that experimental version's Info
  69          ;; files override the ones in standard directories.
  70          (dirs
  71           (if (member config-dir standard-info-dirs)
  72               ;; FIXME?  What is the point of adding it again at the end
  73               ;; when it is already present earlier in the list?
  74               (nconc standard-info-dirs (list config-dir))
  75             (cons config-dir standard-info-dirs))))
  76     (if (not (eq system-type 'windows-nt))
  77         dirs
  78       ;; Include the info directory near where Emacs executable was installed.
  79       (let* ((instdir (file-name-directory invocation-directory))
  80              (dir1 (expand-file-name "../info/" instdir))
  81              (dir2 (expand-file-name "../../../info/" instdir)))
  82         (cond ((file-exists-p dir1) (append dirs (list dir1)))
  83               ((file-exists-p dir2) (append dirs (list dir2)))
  84               (t dirs)))))
  85
  86   "Default list of directories to search for Info documentation files.
  87 They are searched in the order they are given in the list.
  88 Therefore, the directory of Info files that come with Emacs
  89 normally should come last (so that local files override standard ones),
  90 unless Emacs is installed into a non-standard directory.  In the latter
  91 case, the directory of Info files that come with Emacs should be
  92 first in this list.
  93
  94 Once Info is started, the list of directories to search
  95 comes from the variable `Info-directory-list'.
  96 This variable `Info-default-directory-list' is used as the default
  97 for initializing `Info-directory-list' when Info is started, unless
  98 the environment variable INFOPATH is set.
  99
 100 Although this is a customizable variable, that is mainly for technical
 101 reasons.  Normally, you should either set INFOPATH or customize
 102 `Info-additional-directory-list', rather than changing this variable."
 103   :initialize 'custom-initialize-delay
 104   :type '(repeat directory)
 105   :group 'info)
 106
 107
 108 ;;; paths.el ends here