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emacs/lisp/url/url-file.el
Stefan Monnier 9d47364634 * lisp/url/url-file.el (url-file): Don't bind coding-system-for-read
Binding it causes errors when some of the enclosed code ends up
loading a `.el` file, and it is unnecessary since the rest of
the code (in `url-file-asynch-callback`) is already careful to
use `insert-file-contents-literally`.
2022-10-08 23:06:45 -04:00

226 lines
8.0 KiB
EmacsLisp

;;; url-file.el --- File retrieval code -*- lexical-binding:t -*-
;; Copyright (C) 1996-1999, 2004-2022 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 of the License, 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. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;;; Code:
(require 'mailcap)
(require 'url-vars)
(require 'url-parse)
(declare-function mm-disable-multibyte "mm-util" ())
(defvar url-allow-non-local-files nil
"If non-nil, allow URL to fetch non-local files.
By default, this is not allowed, since that would allow rendering
HTML to fetch files on other systems if given a <img
src=\"/ssh:host...\"> element, which can be disturbing.")
(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 _)
"Find the exact file referenced by `fname'.
This tries the common compression extensions, because things like
ange-ftp is 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" ".xz"))
(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))
(with-current-buffer buff
(goto-char (point-max))
(insert-file-contents-literally name)
(insert (format "Content-length: %d\n\n" (buffer-size)))
(if (not (url-file-host-is-local-p (url-host url-current-object)))
(condition-case ()
(delete-file name)
(error nil)))
(apply func args)))
(declare-function ange-ftp-set-passwd "ange-ftp" (host user passwd))
(declare-function ange-ftp-copy-file-internal "ange-ftp"
(filename newname ok-if-already-exists
keep-date &optional msg cont nowait))
(defun url-file-build-filename (url)
(if (not (url-p 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 (cond
;; ftp: URL.
((or user (not (url-file-host-is-local-p host)))
(concat "/" (or user "anonymous") "@" site ":" file))
;; file: URL on Windows.
((and (string-match "\\`/[a-zA-Z]:/" file)
(memq system-type '(ms-dos windows-nt)))
(substring file 1))
;; file: URL with a file:/bar:/foo-like spec.
((and (not url-allow-non-local-files)
(string-match "\\`/[^/]+:/" file))
(concat "/:" file))
(t
file))))
(and user pass
(cond
((featurep 'ange-ftp)
(ange-ftp-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)))
;; (setf (url-filename url)
;; (format "%s%c" filename directory-sep-char)))
(if (and (file-directory-p filename)
(not (string-match "/\\'" filename)))
(setf (url-filename url) (format "%s/" 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)
(filename (url-file-build-filename url)))
(or 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.
;; FIXME should this regexp not include more extensions; basically
;; everything that url-file-find-possibly-compressed-file does?
(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 (pcase (url-file-extension filename)
((or ".z" ".gz") "gzip")
(".Z" "compress")
(".uue" "x-uuencoded")
(".hqx" "x-hqx")
(".bz2" "x-bzip2")
(".xz" "x-xz")
(_ nil)))
(if (file-directory-p filename)
;; A directory is done the same whether we are local or remote
(find-file filename)
(with-current-buffer
(setq buffer (generate-new-buffer " *url-file*"))
(require 'mm-util)
(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 ((new (make-temp-file
(format "url-tmp.%d" (user-real-uid)))))
(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))))))
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)
;;; url-file.el ends here