--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lisp/tl/file-detect.el	Mon Aug 13 08:46:56 2007 +0200
@@ -0,0 +1,140 @@
+;;; file-detect.el --- Emacs Lisp file detection utility
+
+;; Copyright (C) 1996 Free Software Foundation, Inc.
+
+;; Author: MORIOKA Tomohiko <morioka@jaist.ac.jp>
+;; Version:
+;;	$Id: file-detect.el,v 1.1.1.1 1996/12/18 03:55:31 steve Exp $
+;; Keywords: install, module
+
+;; This file is part of tl (Tiny 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 This program; 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'
+
+\[file-detect.el]"
+  (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 get-latest-path (pat &optional all-paths)
+  "Return latest directory in default-load-path
+which is matched to regexp PAT.
+If optional argument ALL-PATHS is specified,
+it is searched from all of load-path instead of default-load-path.
+\[file-detect.el]"
+  (catch 'tag
+    (let ((paths (if all-paths
+		    load-path
+		  default-load-path))
+	  dir)
+      (while (setq dir (car paths))
+	(let ((files (sort (directory-files dir t pat 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 t if FILE exists in PATHS.
+If PATHS is omitted, `load-path' is used. [file-detect.el]"
+  (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))
+	))))
+
+(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. [file-detect.el]"
+  (or (featurep module)
+      (let ((name (symbol-name module)))
+	(if (null paths)
+	    (setq paths load-path)
+	  )
+	(catch 'tag
+	  (while paths
+	    (let ((file (expand-file-name name (car paths))))
+	      (let ((elc-file (concat file ".elc")))
+		(if (file-exists-p elc-file)
+		    (throw 'tag elc-file)
+		  ))
+	      (let ((el-file (concat file ".el")))
+		(if (file-exists-p el-file)
+		    (throw 'tag el-file)
+		  ))
+	      (if (file-exists-p file)
+		  (throw 'tag file)
+		)
+	      )
+	    (setq paths (cdr paths))
+	    )))))
+
+
+;;; @ end
+;;;
+
+(provide 'file-detect)
+
+;;; file-detect.el ends here