--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lisp/apel/file-detect.el	Mon Aug 13 09:39:39 2007 +0200
@@ -0,0 +1,161 @@
+;;; file-detect.el --- Emacs Lisp file detection utility
+
+;; Copyright (C) 1996,1997 Free Software Foundation, Inc.
+
+;; Author: MORIOKA Tomohiko <morioka@jaist.ac.jp>
+;; Version:
+;;	$Id: file-detect.el,v 1.1 1997/06/03 04:18:35 steve Exp $
+;; Keywords: 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)
+
+(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)
+		))
+      )))
+
+(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. [file-detect.el]"
+  (let ((path (get-latest-path pattern all-paths)))
+    (if path
+	(add-to-list 'load-path path)
+      )))
+
+(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))
+	))))
+
+(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))
+	))))
+
+(defvar exec-suffix-list '("")
+  "*List of suffixes for executable.")
+
+(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))
+      )))
+
+(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 'file-detect)
+
+;;; file-detect.el ends here