--- /dev/null
+;;; path-util.el --- Emacs Lisp file detection utility
+
+;; Copyright (C) 1996,1997 Free Software Foundation, Inc.
+
+;; Author: MORIOKA Tomohiko <morioka@jaist.ac.jp>
+;; Version: $Id: path-util.el,v 1.1 1997-11-06 15:47:23 morioka Exp $
+;; Keywords: file detection, install, module
+
+;; This file is part of APEL (A Portable Emacs Library).
+
+;; This program is free software; you can redistribute it and/or
+;; modify it under the terms of the GNU General Public License as
+;; published by the Free Software Foundation; either version 2, or (at
+;; your option) any later version.
+
+;; This program is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING. If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Code:
+
+(defvar default-load-path load-path
+ "*Base of `load-path'.
+It is used as default value of target path to search file or
+subdirectory under load-path.")
+
+;;;###autoload
+(defun add-path (path &rest options)
+ "Add PATH to `load-path' if it exists under `default-load-path'
+directories and it does not exist in `load-path'.
+
+You can use following PATH styles:
+ load-path relative: \"PATH/\"
+ (it is searched from `defaul-load-path')
+ home directory relative: \"~/PATH/\" \"~USER/PATH/\"
+ absolute path: \"/HOO/BAR/BAZ/\"
+
+You can specify following OPTIONS:
+ 'all-paths search from `load-path'
+ instead of `default-load-path'
+ 'append add PATH to the last of `load-path'"
+ (let ((rest (if (memq 'all-paths options)
+ load-path
+ default-load-path))
+ p)
+ (if (and (catch 'tag
+ (while rest
+ (setq p (expand-file-name path (car rest)))
+ (if (file-directory-p p)
+ (throw 'tag p)
+ )
+ (setq rest (cdr rest))
+ ))
+ (not (member p load-path))
+ )
+ (setq load-path
+ (if (memq 'append options)
+ (append load-path (list p))
+ (cons p load-path)
+ ))
+ )))
+
+;;;###autoload
+(defun add-latest-path (pattern &optional all-paths)
+ "Add latest path matched by PATTERN to `load-path'
+if it exists under `default-load-path' directories
+and it does not exist in `load-path'.
+
+If optional argument ALL-PATHS is specified, it is searched from all
+of load-path instead of default-load-path."
+ (let ((path (get-latest-path pattern all-paths)))
+ (if path
+ (add-to-list 'load-path path)
+ )))
+
+;;;###autoload
+(defun get-latest-path (pattern &optional all-paths)
+ "Return latest directory in default-load-path
+which is matched to regexp PATTERN.
+If optional argument ALL-PATHS is specified,
+it is searched from all of load-path instead of default-load-path."
+ (catch 'tag
+ (let ((paths (if all-paths
+ load-path
+ default-load-path))
+ dir)
+ (while (setq dir (car paths))
+ (if (and (file-exists-p dir)
+ (file-directory-p dir)
+ )
+ (let ((files (sort (directory-files dir t pattern t)
+ (function file-newer-than-file-p)))
+ file)
+ (while (setq file (car files))
+ (if (file-directory-p file)
+ (throw 'tag file)
+ )
+ (setq files (cdr files))
+ )))
+ (setq paths (cdr paths))
+ ))))
+
+;;;###autoload
+(defun file-installed-p (file &optional paths)
+ "Return absolute-path of FILE if FILE exists in PATHS.
+If PATHS is omitted, `load-path' is used."
+ (if (null paths)
+ (setq paths load-path)
+ )
+ (catch 'tag
+ (let (path)
+ (while paths
+ (setq path (expand-file-name file (car paths)))
+ (if (file-exists-p path)
+ (throw 'tag path)
+ )
+ (setq paths (cdr paths))
+ ))))
+
+;;;###autoload
+(defvar exec-suffix-list '("")
+ "*List of suffixes for executable.")
+
+;;;###autoload
+(defun exec-installed-p (file &optional paths suffixes)
+ "Return absolute-path of FILE if FILE exists in PATHS.
+If PATHS is omitted, `exec-path' is used.
+If suffixes is omitted, `exec-suffix-list' is used."
+ (or paths
+ (setq paths exec-path)
+ )
+ (or suffixes
+ (setq suffixes exec-suffix-list)
+ )
+ (catch 'tag
+ (while paths
+ (let ((stem (expand-file-name file (car paths)))
+ (sufs suffixes)
+ )
+ (while sufs
+ (let ((file (concat stem (car sufs))))
+ (if (file-exists-p file)
+ (throw 'tag file)
+ ))
+ (setq sufs (cdr sufs))
+ ))
+ (setq paths (cdr paths))
+ )))
+
+;;;###autoload
+(defun module-installed-p (module &optional paths)
+ "Return t if module is provided or exists in PATHS.
+If PATHS is omitted, `load-path' is used."
+ (or (featurep module)
+ (exec-installed-p (symbol-name module) load-path '(".elc" ".el"))
+ ))
+
+
+;;; @ end
+;;;
+
+(provide 'path-util)
+
+;;; path-util.el ends here