root/trunk/lisp/url/url-file.el

;;; url-file.el --- File retrieval code

;; Copyright (C) 1996, 1997, 1998, 1999, 2004,
;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Keywords: comm, data, processes

;; This file is part of GNU Emacs.
;;
;; GNU Emacs 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 3, or (at your option)
;; any later version.
;;
;; GNU Emacs 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., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;;; Code:

(eval-when-compile (require 'cl))
(require 'mailcap)
(require 'url-vars)
(require 'url-parse)
(require 'url-dired)

(defconst url-file-default-port 21 "Default FTP port.")
(defconst url-file-asynchronous-p t "FTP transfers are asynchronous.")
(defalias 'url-file-expand-file-name 'url-default-expander)

(defun url-file-find-possibly-compressed-file (fname &rest args)
  "Find the exact file referenced by `fname'.
This tries the common compression extensions, because things like
ange-ftp and efs are not quite smart enough to realize when a server
can do automatic decompression for them, and won't find 'foo' if
'foo.gz' exists, even though the ftp server would happily serve it up
to them."
  (let ((scratch nil)
        (compressed-extensions '("" ".gz" ".z" ".Z" ".bz2"))
        (found nil))
    (while (and compressed-extensions (not found))
      (if (file-exists-p (setq scratch (concat fname (pop compressed-extensions))))
          (setq found scratch)))
    found))

(defun url-file-host-is-local-p (host)
  "Return t if HOST references our local machine."
  (let ((case-fold-search t))
    (or
     (null host)
     (string= "" host)
     (equal (downcase host) (downcase (system-name)))
     (and (string-match "^localhost$" host) t)
     (and (not (string-match (regexp-quote ".") host))
          (equal (downcase host) (if (string-match (regexp-quote ".")
                                                   (system-name))
                                     (substring (system-name) 0
                                                (match-beginning 0))
                                   (system-name)))))))

(defun url-file-asynch-callback (x y name buff func args &optional efs)
  (if (not (featurep 'ange-ftp))
      ;; EFS passes us an extra argument
      (setq name buff
            buff func
            func args
            args efs))
  (let ((size (nth 7 (file-attributes name))))
    (with-current-buffer buff
      (goto-char (point-max))
      (if (/= -1 size)
          (insert (format "Content-length: %d\n" size)))
      (insert "\n")
      (insert-file-contents-literally name)
      (if (not (url-file-host-is-local-p (url-host url-current-object)))
          (condition-case ()
              (delete-file name)
            (error nil)))
      (apply func args))))

(defun url-file-build-filename (url)
  (if (not (vectorp url))
      (setq url (url-generic-parse-url url)))
  (let* ((user (url-user url))
         (pass (url-password url))
         (port (url-port url))
         (host (url-host url))
         (site (if (and port (/= port 21))
                   (if (featurep 'ange-ftp)
                       (format "%s %d" host port)
                     ;; This works in Emacs 21's ange-ftp too.
                     (format "%s#%d" host port))
                 host))
         (file (url-unhex-string (url-filename url)))
         (filename (if (or user (not (url-file-host-is-local-p host)))
                       (concat "/" (or user "anonymous") "@" site ":" file)
                     (if (and (memq system-type
                                    '(emx ms-dos windows-nt ms-windows))
                              (string-match "^/[a-zA-Z]:/" file))
                         (substring file 1)
                       file)))
         pos-index)

    (and user pass
         (cond
          ((featurep 'ange-ftp)
           (ange-ftp-set-passwd host user pass))
          ((or (featurep 'efs) (featurep 'efs-auto))
           (efs-set-passwd host user pass))
          (t
           nil)))

    ;; This makes sure that directories have a trailing directory
    ;; separator on them so URL expansion works right.
    ;;
    ;; FIXME?  What happens if the remote system doesn't use our local
    ;; directory-sep-char as its separator?  Would it be safer to just
    ;; use '/' unconditionally and rely on the FTP server to
    ;; straighten it out for us?
    ;; (if (and (file-directory-p filename)
    ;;          (not (string-match (format "%c$" directory-sep-char) filename)))
    ;;     (url-set-filename url (format "%s%c" filename directory-sep-char)))
    (if (and (file-directory-p filename)
             (not (string-match "/\\'" filename)))
        (url-set-filename url (format "%s/" filename)))


    ;; If it is a directory, look for an index file first.
    (if (and (file-directory-p filename)
             url-directory-index-file
             (setq pos-index (expand-file-name url-directory-index-file filename))
             (file-exists-p pos-index)
             (file-readable-p pos-index))
        (setq filename pos-index))

    ;; Find the (possibly compressed) file
    (setq filename (url-file-find-possibly-compressed-file filename))
    filename))

;;;###autoload
(defun url-file (url callback cbargs)
  "Handle file: and ftp: URLs."
  (let* ((buffer nil)
         (uncompressed-filename nil)
         (content-type nil)
         (content-encoding nil)
         (coding-system-for-read 'binary))

    (setq filename (url-file-build-filename url))

    (if (not filename)
        (error "File does not exist: %s" (url-recreate-url url)))

    ;; Need to figure out the content-type from the real extension,
    ;; not the compressed one.
    (setq uncompressed-filename (if (string-match "\\.\\(gz\\|Z\\|z\\)$" filename)
                                    (substring filename 0 (match-beginning 0))
                                  filename))
    (setq content-type (mailcap-extension-to-mime
                        (url-file-extension uncompressed-filename))
          content-encoding (case (intern (url-file-extension filename))
                             ((\.z \.gz) "gzip")
                             (\.Z "compress")
                             (\.uue "x-uuencoded")
                             (\.hqx "x-hqx")
                             (\.bz2 "x-bzip2")
                             (otherwise nil)))

    (if (file-directory-p filename)
        ;; A directory is done the same whether we are local or remote
        (url-find-file-dired filename)
      (with-current-buffer
          (setq buffer (generate-new-buffer " *url-file*"))
        (mm-disable-multibyte)
        (setq url-current-object url)
        (insert "Content-type: " (or content-type "application/octet-stream") "\n")
        (if content-encoding
            (insert "Content-transfer-encoding: " content-encoding "\n"))
        (if (url-file-host-is-local-p (url-host url))
              ;; Local files are handled slightly oddly
            (if (featurep 'ange-ftp)
                (url-file-asynch-callback nil nil
                                          filename
                                          (current-buffer)
                                          callback cbargs)
              (url-file-asynch-callback nil nil nil
                                        filename
                                        (current-buffer)
                                        callback cbargs))
          ;; FTP handling
          (let* ((extension (url-file-extension filename))
                 (new (url-generate-unique-filename
                       (and (> (length extension) 0)
                            (concat "%s." extension)))))
            (if (featurep 'ange-ftp)
                (ange-ftp-copy-file-internal filename (expand-file-name new) t
                                             nil t
                                             (list 'url-file-asynch-callback
                                                   new (current-buffer)
                                                   callback cbargs)
                                             t)
              (autoload 'efs-copy-file-internal "efs")
              (efs-copy-file-internal filename (efs-ftp-path filename)
                                      new (efs-ftp-path new)
                                      t nil 0
                                      (list 'url-file-asynch-callback
                                            new (current-buffer)
                                            callback cbargs)
                                      0 nil))))))
    buffer))

(defmacro url-file-create-wrapper (method args)
  `(defalias ',(intern (format "url-ftp-%s" method))
     (defun ,(intern (format "url-file-%s" method)) ,args
       ,(format "FTP/FILE URL wrapper around `%s' call." method)
       (setq url (url-file-build-filename url))
       (and url (,method ,@(remove '&rest (remove '&optional args)))))))

(url-file-create-wrapper file-exists-p (url))
(url-file-create-wrapper file-attributes (url &optional id-format))
(url-file-create-wrapper file-symlink-p (url))
(url-file-create-wrapper file-readable-p (url))
(url-file-create-wrapper file-writable-p (url))
(url-file-create-wrapper file-executable-p (url))
(url-file-create-wrapper directory-files (url &optional full match nosort))
(url-file-create-wrapper file-truename (url &optional counter prev-dirs))

(provide 'url-file)

;; arch-tag: 010e914a-7313-494b-8a8c-6495a862157d
;;; url-file.el ends here