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;;; -*- Log: code.log; Package: Lisp -*-
;;; **********************************************************************
;;; This code was written as part of the CMU Common Lisp project at
;;; Carnegie Mellon University, and has been placed in the public domain.
;;; If you want to use this code or any part of CMU Common Lisp, please contact
;;; Scott Fahlman or slisp-group@cs.cmu.edu.
;;;
(ext:file-comment
  "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/filesys.lisp,v 1.75 2003/06/11 16:40:02 toy Exp $")
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;;; **********************************************************************
;;;
;;; File system interface functions.  This file is pretty UNIX specific.
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;;;
;;; Written by William Lott
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;;;
;;; **********************************************************************
(export '(truename probe-file user-homedir-pathname directory
          rename-file delete-file file-write-date file-author))
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(use-package "EXTENSIONS")

(in-package "EXTENSIONS")
(export '(print-directory complete-file ambiguous-files default-directory
	  purge-backup-files file-writable unix-namestring))
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;;;; Unix pathname host support.
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;;; Unix namestrings have the following format:
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;;;
;;; namestring := [ directory ] [ file [ type [ version ]]]
;;; directory := [ "/" | search-list ] { file "/" }*
;;; search-list := [^:/]*:
;;; file := [^/]*
;;; type := "." [^/.]*
;;; version := ".*" | ".~" ([0-9]+ | "*") "~"
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;;;
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;;; Note: this grammar is ambiguous.  The string foo.bar.~5~ can be parsed
;;; as either just the file specified or as specifying the file, type, and
;;; version.  Therefore, we use the following rules when confronted with
;;; an ambiguous file.type.version string:
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;;;
;;; - If the first character is a dot, it's part of the file.  It is not
;;; considered a dot in the following rules.
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;;;
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;;; - If there is only one dot, it separates the file and the type.
;;;
;;; - If there are multiple dots and the stuff following the last dot
;;; is a valid version, then that is the version and the stuff between
;;; the second to last dot and the last dot is the type.
;;;
;;; Wildcard characters:
;;;
;;; If the directory, file, type components contain any of the following
;;; characters, it is considered part of a wildcard pattern and has the
;;; following meaning.
;;;
;;; ? - matches any character
;;; * - matches any zero or more characters.
;;; [abc] - matches any of a, b, or c.
;;; {str1,str2,...,strn} - matches any of str1, str2, ..., or strn.
;;;
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;;; Any of these special characters can be preceded by a backslash to
;;; cause it to be treated as a regular character.
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;;;

(defun remove-backslashes (namestr start end)
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  "Remove any occurrences of \\ from the string because we've already
   checked for whatever may have been backslashed."
  (declare (type simple-base-string namestr)
	   (type index start end))
  (let* ((result (make-string (- end start)))
	 (dst 0)
	 (quoted nil))
    (do ((src start (1+ src)))
	((= src end))
      (cond (quoted
	     (setf (schar result dst) (schar namestr src))
	     (setf quoted nil)
	     (incf dst))
	    (t
	     (let ((char (schar namestr src)))
	       (cond ((char= char #\\)
		      (setq quoted t))
		     (t
		      (setf (schar result dst) char)
		      (incf dst)))))))
    (when quoted
      (error 'namestring-parse-error
	     :complaint "Backslash in bad place."
	     :namestring namestr
	     :offset (1- end)))
    (shrink-vector result dst)))

(defvar *ignore-wildcards* nil)

(defun maybe-make-pattern (namestr start end)
  (declare (type simple-base-string namestr)
	   (type index start end))
  (if *ignore-wildcards*
      (subseq namestr start end)
      (collect ((pattern))
	(let ((quoted nil)
	      (any-quotes nil)
	      (last-regular-char nil)
	      (index start))
	  (flet ((flush-pending-regulars ()
		   (when last-regular-char
		     (pattern (if any-quotes
				  (remove-backslashes namestr
						      last-regular-char
						      index)
				  (subseq namestr last-regular-char index)))
		     (setf any-quotes nil)
		     (setf last-regular-char nil))))
	    (loop
	      (when (>= index end)
		(return))
	      (let ((char (schar namestr index)))
		(cond (quoted
		       (incf index)
		       (setf quoted nil))
		      ((char= char #\\)
		       (setf quoted t)
		       (setf any-quotes t)
		       (unless last-regular-char
			 (setf last-regular-char index))
		       (incf index))
		      ((char= char #\?)
		       (flush-pending-regulars)
		       (pattern :single-char-wild)
		       (incf index))
		      ((char= char #\*)
		       (flush-pending-regulars)
		       (pattern :multi-char-wild)
		       (incf index))
		      ((char= char #\[)
		       (flush-pending-regulars)
		       (let ((close-bracket
			      (position #\] namestr :start index :end end)))
			 (unless close-bracket
			   (error 'namestring-parse-error
				  :complaint "``['' with no corresponding ``]''"
				  :namestring namestr
				  :offset index))
			 (pattern (list :character-set
					(subseq namestr
						(1+ index)
						close-bracket)))
			 (setf index (1+ close-bracket))))
		      (t
		       (unless last-regular-char
			 (setf last-regular-char index))
		       (incf index)))))
	    (flush-pending-regulars)))
	(cond ((null (pattern))
	       "")
	      ((null (cdr (pattern)))
	       (let ((piece (first (pattern))))
		 (typecase piece
		   ((member :multi-char-wild) :wild)
		   (simple-string piece)
		   (t
		    (make-pattern (pattern))))))
;;; extract-name-type-and-version  --  Internal.
;;;
(defun extract-name-type-and-version (namestr start end)
  (declare (type simple-base-string namestr)
	   (type index start end))
  (labels
      ((explicit-version (namestr start end)
	 (cond ((or (< (- end start) 5)
		    (char/= (schar namestr (1- end)) #\~))
		;; No explicit version given, so return NIL to
		;; indicate we don't want file versions, unless
		;; requested in other ways.
		(values nil end))
	       ((and (char= (schar namestr (- end 2)) #\*)
		     (char= (schar namestr (- end 3)) #\~)
		     (char= (schar namestr (- end 4)) #\.))
		(values :wild (- end 4)))
	       (t
		(do ((i (- end 2) (1- i)))
		    ((< i (+ start 2)) (values :newest end))
		  (let ((char (schar namestr i)))
		    (when (eql char #\~)
		      (return (if (char= (schar namestr (1- i)) #\.)
				  (values (parse-integer namestr :start (1+ i)
							 :end (1- end))
					  (1- i))
				  (values :newest end))))
		    (unless (char<= #\0 char #\9)
		      (return (values :newest end))))))))
       (any-version (namestr start end)
	 ;; process end of string looking for a version candidate.
	 (multiple-value-bind (version where)
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	     (explicit-version namestr start end)
	   (cond ((not (eq version :newest))
		  (values version where))
		 ((and (>= (- end 2) start)
		       (char= (schar namestr (- end 1)) #\*)
		       (char= (schar namestr (- end 2)) #\.)
		       (find #\. namestr
			     :start (min (1+ start) (- end 2))
			     :end (- end 2)))
		  (values :wild (- end 2)))
		 (t (values version where)))))
       (any-type (namestr start end)
	 ;; Process end of string looking for a type. A leading "."
	 ;; is part of the name.
	 (let ((where (position #\. namestr
				:start (min (1+ start) end)
				:end end :from-end t)))
	   (when where
	     (values where end))))
       (any-name (namestr start end)
	 (declare (ignore namestr))
	 (values start end)))
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    (multiple-value-bind (version vstart)
	(any-version namestr start end)
      (multiple-value-bind (tstart tend)
	  (any-type namestr start vstart)
	(multiple-value-bind (nstart nend)
	    (any-name namestr start (or tstart vstart))
	  (values
	   (maybe-make-pattern namestr nstart nend)
	   (and tstart (maybe-make-pattern namestr (1+ tstart) tend))
	   version))))))
;;; Take a string and return a list of cons cells that mark the char
;;; separated subseq. The first value t if absolute directories location.
;;;
(defun split-at-slashes (namestr start end)
  (declare (type simple-base-string namestr)
	   (type index start end))
  (let ((absolute (and (/= start end)
		       (char= (schar namestr start) #\/))))
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    ;; Next, split the remainder into slash separated chunks.
	(let ((slash (position #\/ namestr :start start :end end)))
	  (pieces (cons start (or slash end)))
	  (unless slash
      (values absolute (pieces)))))

(defun maybe-extract-search-list (namestr start end)
  (declare (type simple-base-string namestr)
	   (type index start end))
  (let ((quoted nil))
    (do ((index start (1+ index)))
	((= index end)
	 (values nil start))
      (if quoted
	  (setf quoted nil)
	  (case (schar namestr index)
	    (#\\
	     (setf quoted t))
	    (#\:
	     (return (values (remove-backslashes namestr start index)
			     (1+ index)))))))))

(defun parse-unix-namestring (namestr start end)
  (declare (type simple-base-string namestr)
	   (type index start end))
  (multiple-value-bind
      (absolute pieces)
      (split-at-slashes namestr start end)
    (let ((search-list
	   (if absolute
	       nil
	       (let ((first (car pieces)))
		 (multiple-value-bind
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		       (search-list new-start)
		     (maybe-extract-search-list namestr
						(car first) (cdr first))
		   (when search-list
		     (setf absolute t)
		     (setf (car first) new-start))
		   search-list)))))
      (multiple-value-bind
	  (name type version)
	  (let* ((tail (car (last pieces)))
		 (tail-start (car tail))
		 (tail-end (cdr tail)))
	    (unless (= tail-start tail-end)
	      (setf pieces (butlast pieces))
	      (extract-name-type-and-version namestr tail-start tail-end)))
	;; PVE: Make sure there are no illegal characters in the name
	;; such as #\Null and #\/.
	(when (and (stringp name)
                   (find-if #'(lambda (x)
				(or (char= x #\Null) (char= x #\/)))
			    name))
	  (error 'parse-error))
	;; Now we have everything we want.  So return it.
	(values nil ; no host for unix namestrings.
		nil ; no devices for unix namestrings.
		(collect ((dirs))
		  (when search-list
		    (dirs (intern-search-list search-list)))
		  (dolist (piece pieces)
		    (let ((piece-start (car piece))
			  (piece-end (cdr piece)))
		      (unless (= piece-start piece-end)
			(cond ((string= namestr ".." :start1 piece-start
					:end1 piece-end)
			       (dirs :up))
			      ((string= namestr "**" :start1 piece-start
					:end1 piece-end)
			       (dirs :wild-inferiors))
			      (t
			       (dirs (maybe-make-pattern namestr
							 piece-start
							 piece-end)))))))
		  (cond (absolute
			 (cons :absolute (dirs)))
			((dirs)
			 (cons :relative (dirs)))
			(t
			 nil)))
		name
		type
		version)))))

(defun unparse-unix-host (pathname)
  (declare (type pathname pathname)
	   (ignore pathname))
  ;; this host designator needs to be recognized as a physical host in
  ;; PARSE-NAMESTRING. Until sbcl-0.7.3.x, we had "Unix" here, but
  ;; that's a valid Logical Hostname, so that's a bad choice. -- CSR,
  "")

(defun unparse-unix-piece (thing)
  (etypecase thing
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