lisp/url/url-file.el

   1 ;;; url-file.el --- File retrieval code
   2
   3 ;; Copyright (C) 1996-1999, 2004-2015 Free Software Foundation, Inc.
   4
   5 ;; Keywords: comm, data, processes
   6
   7 ;; This file is part of GNU Emacs.
   8 ;;
   9 ;; GNU Emacs is free software: you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation, either version 3 of the License, or
  12 ;; (at your option) any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 ;;; Commentary:
  23
  24 ;;; Code:
  25
  26 (require 'mailcap)
  27 (require 'url-vars)
  28 (require 'url-parse)
  29 (require 'url-dired)
  30
  31 (defconst url-file-default-port 21 "Default FTP port.")
  32 (defconst url-file-asynchronous-p t "FTP transfers are asynchronous.")
  33 (defalias 'url-file-expand-file-name 'url-default-expander)
  34
  35 (defun url-file-find-possibly-compressed-file (fname &rest args)
  36   "Find the exact file referenced by `fname'.
  37 This tries the common compression extensions, because things like
  38 ange-ftp and efs are not quite smart enough to realize when a server
  39 can do automatic decompression for them, and won't find 'foo' if
  40 'foo.gz' exists, even though the FTP server would happily serve it up
  41 to them."
  42   (let ((scratch nil)
  43         (compressed-extensions '("" ".gz" ".z" ".Z" ".bz2" ".xz"))
  44         (found nil))
  45     (while (and compressed-extensions (not found))
  46       (if (file-exists-p (setq scratch (concat fname (pop compressed-extensions))))
  47           (setq found scratch)))
  48     found))
  49
  50 (defun url-file-host-is-local-p (host)
  51   "Return t if HOST references our local machine."
  52   (let ((case-fold-search t))
  53     (or
  54      (null host)
  55      (string= "" host)
  56      (equal (downcase host) (downcase (system-name)))
  57      (and (string-match "^localhost$" host) t)
  58      (and (not (string-match (regexp-quote ".") host))
  59           (equal (downcase host) (if (string-match (regexp-quote ".")
  60                                                    (system-name))
  61                                      (substring (system-name) 0
  62                                                 (match-beginning 0))
  63                                    (system-name)))))))
  64
  65 (defun url-file-asynch-callback (x y name buff func args &optional efs)
  66   (if (not (featurep 'ange-ftp))
  67       ;; EFS passes us an extra argument
  68       (setq name buff
  69             buff func
  70             func args
  71             args efs))
  72   (let ((size (nth 7 (file-attributes name))))
  73     (with-current-buffer buff
  74       (goto-char (point-max))
  75       (if (/= -1 size)
  76           (insert (format "Content-length: %d\n" size)))
  77       (insert "\n")
  78       (insert-file-contents-literally name)
  79       (if (not (url-file-host-is-local-p (url-host url-current-object)))
  80           (condition-case ()
  81               (delete-file name)
  82             (error nil)))
  83       (apply func args))))
  84
  85 (declare-function ange-ftp-set-passwd "ange-ftp" (host user passwd))
  86 (declare-function ange-ftp-copy-file-internal "ange-ftp"
  87                   (filename newname ok-if-already-exists
  88                             keep-date &optional msg cont nowait))
  89
  90 (defun url-file-build-filename (url)
  91   (if (not (vectorp url))
  92       (setq url (url-generic-parse-url url)))
  93   (let* ((user (url-user url))
  94          (pass (url-password url))
  95          (port (url-port url))
  96          (host (url-host url))
  97          (site (if (and port (/= port 21))
  98                    (if (featurep 'ange-ftp)
  99                        (format "%s %d" host port)
 100                      ;; This works in Emacs 21's ange-ftp too.
 101                      (format "%s#%d" host port))
 102                  host))
 103          (file (url-unhex-string (url-filename url)))
 104          (filename (cond
 105                     ;; ftp: URL.
 106                     ((or user (not (url-file-host-is-local-p host)))
 107                      (concat "/" (or user "anonymous") "@" site ":" file))
 108                     ;; file: URL on Windows.
 109                     ((and (string-match "\\`/[a-zA-Z]:/" file)
 110                           (memq system-type '(ms-dos windows-nt)))
 111                      (substring file 1))
 112                     ;; file: URL with a file:/bar:/foo-like spec.
 113                     ((string-match "\\`/[^/]+:/" file)
 114                      (concat "/:" file))
 115                     (t
 116                      file)))
 117          pos-index)
 118
 119     (and user pass
 120          (cond
 121           ((featurep 'ange-ftp)
 122            (ange-ftp-set-passwd host user pass))
 123           ((when (featurep 'xemacs)
 124              (or (featurep 'efs) (featurep 'efs-auto)
 125                  (efs-set-passwd host user pass))))
 126           (t
 127            nil)))
 128
 129     ;; This makes sure that directories have a trailing directory
 130     ;; separator on them so URL expansion works right.
 131     ;;
 132     ;; FIXME?  What happens if the remote system doesn't use our local
 133     ;; directory-sep-char as its separator?  Would it be safer to just
 134     ;; use '/' unconditionally and rely on the FTP server to
 135     ;; straighten it out for us?
 136     ;; (if (and (file-directory-p filename)
 137     ;;          (not (string-match (format "%c$" directory-sep-char) filename)))
 138     ;;     (setf (url-filename url)
 139     ;;           (format "%s%c" filename directory-sep-char)))
 140     (if (and (file-directory-p filename)
 141              (not (string-match "/\\'" filename)))
 142         (setf (url-filename url) (format "%s/" filename)))
 143
 144
 145     ;; If it is a directory, look for an index file first.
 146     (if (and (file-directory-p filename)
 147              url-directory-index-file
 148              (setq pos-index (expand-file-name url-directory-index-file filename))
 149              (file-exists-p pos-index)
 150              (file-readable-p pos-index))
 151         (setq filename pos-index))
 152
 153     ;; Find the (possibly compressed) file
 154     (setq filename (url-file-find-possibly-compressed-file filename))
 155     filename))
 156
 157 ;;;###autoload
 158 (defun url-file (url callback cbargs)
 159   "Handle file: and ftp: URLs."
 160   (let* ((buffer nil)
 161          (uncompressed-filename nil)
 162          (content-type nil)
 163          (content-encoding nil)
 164          (coding-system-for-read 'binary)
 165          (filename (url-file-build-filename url)))
 166     (or filename (error "File does not exist: %s" (url-recreate-url url)))
 167     ;; Need to figure out the content-type from the real extension,
 168     ;; not the compressed one.
 169     ;; FIXME should this regexp not include more extensions; basically
 170     ;; everything that url-file-find-possibly-compressed-file does?
 171     (setq uncompressed-filename (if (string-match "\\.\\(gz\\|Z\\|z\\)$" filename)
 172                                     (substring filename 0 (match-beginning 0))
 173                                   filename))
 174     (setq content-type (mailcap-extension-to-mime
 175                         (url-file-extension uncompressed-filename))
 176           content-encoding (pcase (url-file-extension filename)
 177                              ((or ".z" ".gz") "gzip")
 178                              (".Z" "compress")
 179                              (".uue" "x-uuencoded")
 180                              (".hqx" "x-hqx")
 181                              (".bz2" "x-bzip2")
 182                              (".xz" "x-xz")
 183                              (_ nil)))
 184
 185     (if (file-directory-p filename)
 186         ;; A directory is done the same whether we are local or remote
 187         (url-find-file-dired filename)
 188       (with-current-buffer
 189           (setq buffer (generate-new-buffer " *url-file*"))
 190         (mm-disable-multibyte)
 191         (setq url-current-object url)
 192         (insert "Content-type: " (or content-type "application/octet-stream") "\n")
 193         (if content-encoding
 194             (insert "Content-transfer-encoding: " content-encoding "\n"))
 195         (if (url-file-host-is-local-p (url-host url))
 196               ;; Local files are handled slightly oddly
 197             (if (featurep 'ange-ftp)
 198                 (url-file-asynch-callback nil nil
 199                                           filename
 200                                           (current-buffer)
 201                                           callback cbargs)
 202               (url-file-asynch-callback nil nil nil
 203                                         filename
 204                                         (current-buffer)
 205                                         callback cbargs))
 206           ;; FTP handling
 207           (let ((new (make-temp-file
 208                       (format "url-tmp.%d" (user-real-uid)))))
 209             (if (featurep 'ange-ftp)
 210                 (ange-ftp-copy-file-internal filename (expand-file-name new) t
 211                                              nil t
 212                                              (list 'url-file-asynch-callback
 213                                                    new (current-buffer)
 214                                                    callback cbargs)
 215                                              t)
 216               (when (featurep 'xemacs)
 217                 (autoload 'efs-copy-file-internal "efs")
 218                 (efs-copy-file-internal filename (efs-ftp-path filename)
 219                                         new (efs-ftp-path new)
 220                                         t nil 0
 221                                         (list 'url-file-asynch-callback
 222                                               new (current-buffer)
 223                                               callback cbargs)
 224                                         0 nil)))))))
 225     buffer))
 226
 227 (defmacro url-file-create-wrapper (method args)
 228   `(defalias ',(intern (format "url-ftp-%s" method))
 229      (defun ,(intern (format "url-file-%s" method)) ,args
 230        ,(format "FTP/FILE URL wrapper around `%s' call." method)
 231        (setq url (url-file-build-filename url))
 232        (and url (,method ,@(remove '&rest (remove '&optional args)))))))
 233
 234 (url-file-create-wrapper file-exists-p (url))
 235 (url-file-create-wrapper file-attributes (url &optional id-format))
 236 (url-file-create-wrapper file-symlink-p (url))
 237 (url-file-create-wrapper file-readable-p (url))
 238 (url-file-create-wrapper file-writable-p (url))
 239 (url-file-create-wrapper file-executable-p (url))
 240 (url-file-create-wrapper directory-files (url &optional full match nosort))
 241 (url-file-create-wrapper file-truename (url &optional counter prev-dirs))
 242
 243 (provide 'url-file)
 244
 245 ;;; url-file.el ends here