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emacs/lisp/net/tramp-compat.el
2008-03-15 21:50:58 +00:00

242 lines
9.1 KiB
EmacsLisp

;;; tramp-compat.el --- Tramp compatibility functions
;; Copyright (C) 2007, 2008 Free Software Foundation, Inc.
;; Author: Michael Albinus <michael.albinus@gmx.de>
;; Keywords: comm, 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, see
;; <http://www.gnu.org/licenses/>.
;;; Commentary:
;; Tramp's main Emacs version for development is GNU Emacs 23. This
;; package provides compatibility functions for GNU Emacs 21, GNU
;; Emacs 22 and XEmacs 21.4+.
;;; Code:
(eval-when-compile
;; Pacify byte-compiler.
(require 'cl))
(eval-and-compile
(require 'custom)
;; Load the appropriate timer package.
(if (featurep 'xemacs)
(require 'timer-funcs)
(require 'timer))
;; tramp-util offers integration into other (X)Emacs packages like
;; compile.el, gud.el etc. Not necessary in Emacs 23.
(eval-after-load "tramp"
;; We check whether `start-file-process' is an alias.
'(when (or (not (fboundp 'start-file-process))
(symbolp (symbol-function 'start-file-process)))
(require 'tramp-util)
(add-hook 'tramp-unload-hook
'(lambda ()
(when (featurep 'tramp-util)
(unload-feature 'tramp-util 'force))))))
;; Make sure that we get integration with the VC package. When it
;; is loaded, we need to pull in the integration module. Not
;; necessary in Emacs 23.
(eval-after-load "vc"
(eval-after-load "tramp"
;; We check whether `start-file-process' is an alias.
'(when (or (not (fboundp 'start-file-process))
(symbolp (symbol-function 'start-file-process)))
(require 'tramp-vc)
(add-hook 'tramp-unload-hook
'(lambda ()
(when (featurep 'tramp-vc)
(unload-feature 'tramp-vc 'force)))))))
;; Avoid byte-compiler warnings if the byte-compiler supports this.
;; Currently, XEmacs supports this.
(when (featurep 'xemacs)
(unless (boundp 'byte-compile-default-warnings)
(defvar byte-compile-default-warnings nil))
(delq 'unused-vars byte-compile-default-warnings))
;; `last-coding-system-used' is unknown in XEmacs.
(unless (boundp 'last-coding-system-used)
(defvar last-coding-system-used nil))
;; `directory-sep-char' is an obsolete variable in Emacs. But it is
;; used in XEmacs, so we set it here and there. The following is
;; needed to pacify Emacs byte-compiler.
(unless (boundp 'byte-compile-not-obsolete-var)
(defvar byte-compile-not-obsolete-var nil))
(setq byte-compile-not-obsolete-var 'directory-sep-char)
;; `with-temp-message' does not exists in XEmacs.
(condition-case nil
(with-temp-message (current-message) nil)
(error (defmacro with-temp-message (message &rest body) `(progn ,@body))))
;; `set-buffer-multibyte' comes from Emacs Leim.
(unless (fboundp 'set-buffer-multibyte)
(defalias 'set-buffer-multibyte 'ignore))
;; `font-lock-add-keywords' does not exist in XEmacs.
(unless (fboundp 'font-lock-add-keywords)
(defalias 'font-lock-add-keywords 'ignore))
;; `file-remote-p' has been introduced with Emacs 22. The version
;; of XEmacs is not a magic file name function (yet); this is
;; corrected in tramp-util.el. Here it is sufficient if the
;; function exists.
(unless (fboundp 'file-remote-p)
(defalias 'file-remote-p 'tramp-handle-file-remote-p))
;; `process-file' exists since Emacs 22.
(unless (fboundp 'process-file)
(defalias 'process-file 'tramp-handle-process-file))
;; `start-file-process' is new in Emacs 23.
(unless (fboundp 'start-file-process)
(defalias 'start-file-process 'tramp-handle-start-file-process))
;; `set-file-times' is also new in Emacs 23.
(unless (fboundp 'set-file-times)
(defalias 'set-file-times 'tramp-handle-set-file-times)))
(defsubst tramp-compat-line-end-position ()
"Return point at end of line (compat function).
Calls `line-end-position' or `point-at-eol' if defined, else
own implementation."
(cond
((fboundp 'line-end-position) (funcall (symbol-function 'line-end-position)))
((fboundp 'point-at-eol) (funcall (symbol-function 'point-at-eol)))
(t (save-excursion (end-of-line) (point)))))
(defsubst tramp-compat-temporary-file-directory ()
"Return name of directory for temporary files (compat function).
For Emacs, this is the variable `temporary-file-directory', for XEmacs
this is the function `temp-directory'."
(cond
((boundp 'temporary-file-directory) (symbol-value 'temporary-file-directory))
((fboundp 'temp-directory) (funcall (symbol-function 'temp-directory)))
((let ((d (getenv "TEMP"))) (and d (file-directory-p d)))
(file-name-as-directory (getenv "TEMP")))
((let ((d (getenv "TMP"))) (and d (file-directory-p d)))
(file-name-as-directory (getenv "TMP")))
((let ((d (getenv "TMPDIR"))) (and d (file-directory-p d)))
(file-name-as-directory (getenv "TMPDIR")))
((file-exists-p "c:/temp") (file-name-as-directory "c:/temp"))
(t (message (concat "Neither `temporary-file-directory' nor "
"`temp-directory' is defined -- using /tmp."))
(file-name-as-directory "/tmp"))))
;; `make-temp-file' exists in Emacs only. The third parameter SUFFIX
;; has been introduced with Emacs 22. We try it, if it fails, we fall
;; back to `make-temp-name', creating the temporary file immediately
;; in order to avoid a security hole.
(defsubst tramp-compat-make-temp-file (filename)
"Create a temporary file (compat function).
Add the extension of FILENAME, if existing."
(let ((prefix (expand-file-name
(symbol-value 'tramp-temp-name-prefix)
(tramp-compat-temporary-file-directory)))
(extension (file-name-extension filename t))
result)
(condition-case nil
(setq result
(funcall (symbol-function 'make-temp-file) prefix nil extension))
(error
;; We use our own implementation, taken from files.el.
(while
(condition-case ()
(progn
(setq result (concat (make-temp-name prefix) extension))
(write-region
"" nil result nil 'silent nil
;; 7th parameter is MUSTBENEW in Emacs, and
;; CODING-SYSTEM in XEmacs. It is not a security
;; hole in XEmacs if we cannot use this parameter,
;; because XEmacs uses a user-specific subdirectory
;; with 0700 permissions.
(when (not (featurep 'xemacs)) 'excl))
nil)
(file-already-exists t))
;; The file was somehow created by someone else between
;; `make-temp-name' and `write-region', let's try again.
nil)))
result))
;; `most-positive-fixnum' arrived in Emacs 22. Before, and in XEmacs,
;; it is a fixed value.
(defsubst tramp-compat-most-positive-fixnum ()
"Return largest positive integer value (compat function)."
(cond
((boundp 'most-positive-fixnum) (symbol-value 'most-positive-fixnum))
;; Default value in XEmacs and Emacs 21.
(t 134217727)))
;; ID-FORMAT exists since Emacs 22.
(defun tramp-compat-file-attributes (filename &optional id-format)
"Like `file-attributes' for Tramp files (compat function)."
(cond
((or (null id-format) (eq id-format 'integer))
(file-attributes filename))
;; FIXME: shouldn't that be tramp-file-p or somesuch?
((file-remote-p filename)
(funcall (symbol-function 'tramp-handle-file-attributes)
filename id-format))
(t (condition-case nil
(funcall (symbol-function 'file-attributes) filename id-format)
(error (file-attributes filename))))))
;; PRESERVE-UID-GID has been introduced with Emacs 23. It does not
;; hurt to ignore it for other (X)Emacs versions.
(defun tramp-compat-copy-file
(filename newname &optional ok-if-already-exists keep-date preserve-uid-gid)
"Like `copy-file' for Tramp files (compat function)."
(if preserve-uid-gid
(funcall
(symbol-function 'copy-file)
filename newname ok-if-already-exists keep-date preserve-uid-gid)
(copy-file filename newname ok-if-already-exists keep-date)))
;; `copy-tree' is a built-in function in XEmacs. In Emacs 21, it is
;; an autoloaded function in cl-extra.el. Since Emacs 22, it is part
;; of subr.el. There are problems when autoloading, therefore we test
;; for `subrp' and `symbol-file'. Implementation is taken from Emacs23.
(defun tramp-compat-copy-tree (tree)
"Make a copy of TREE (compat function)."
(if (or (subrp 'copy-tree) (symbol-file 'copy-tree))
(funcall (symbol-function 'copy-tree) tree)
(let (result)
(while (consp tree)
(let ((newcar (car tree)))
(if (consp (car tree))
(setq newcar (tramp-compat-copy-tree (car tree))))
(push newcar result))
(setq tree (cdr tree)))
(nconc (nreverse result) tree))))
(provide 'tramp-compat)
;;; TODO:
;; arch-tag: 0e724b18-6699-4f87-ad96-640b272e5c85
;;; tramp-compat.el ends here