lisp/net/tramp-compat.el

   1 ;;; tramp-compat.el --- Tramp compatibility functions  -*- lexical-binding:t -*-
   2
   3 ;; Copyright (C) 2007-2018 Free Software Foundation, Inc.
   4
   5 ;; Author: Michael Albinus <michael.albinus@gmx.de>
   6 ;; Keywords: comm, processes
   7 ;; Package: tramp
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; Tramp's main Emacs version for development is Emacs 27.  This
  27 ;; package provides compatibility functions for Emacs 24, Emacs 25 and
  28 ;; Emacs 26.
  29
  30 ;;; Code:
  31
  32 (require 'auth-source)
  33 (require 'advice)
  34 (require 'cl-lib)
  35 (require 'custom)
  36 (require 'format-spec)
  37 (require 'parse-time)
  38 (require 'password-cache)
  39 (require 'shell)
  40 (require 'timer)
  41 (require 'ucs-normalize)
  42
  43 (require 'trampver)
  44 (require 'tramp-loaddefs)
  45
  46 ;; For not existing functions, obsolete functions, or functions with a
  47 ;; changed argument list, there are compiler warnings.  We want to
  48 ;; avoid them in cases we know what we do.
  49 (defmacro tramp-compat-funcall (function &rest arguments)
  50   "Call FUNCTION if it exists.  Do not raise compiler warnings."
  51   `(when (functionp ,function)
  52      (with-no-warnings (funcall ,function ,@arguments))))
  53
  54 (defsubst tramp-compat-temporary-file-directory ()
  55   "Return name of directory for temporary files.
  56 It is the default value of `temporary-file-directory'."
  57   ;; We must return a local directory.  If it is remote, we could run
  58   ;; into an infloop.
  59   (eval (car (get 'temporary-file-directory 'standard-value))))
  60
  61 (defsubst tramp-compat-make-temp-file (f &optional dir-flag)
  62   "Create a local temporary file (compat function).
  63 Add the extension of F, if existing."
  64   (let* (file-name-handler-alist
  65          (prefix (expand-file-name
  66                   (symbol-value 'tramp-temp-name-prefix)
  67                   (tramp-compat-temporary-file-directory)))
  68          (extension (file-name-extension f t)))
  69     (make-temp-file prefix dir-flag extension)))
  70
  71 ;; `temporary-file-directory' as function is introduced with Emacs 26.1.
  72 (defalias 'tramp-compat-temporary-file-directory-function
  73   (if (fboundp 'temporary-file-directory)
  74       'temporary-file-directory
  75     'tramp-handle-temporary-file-directory))
  76
  77 (defun tramp-compat-process-running-p (process-name)
  78   "Returns t if system process PROCESS-NAME is running for `user-login-name'."
  79   (when (stringp process-name)
  80     (cond
  81      ;; GNU Emacs 22 on w32.
  82      ((fboundp 'w32-window-exists-p)
  83       (tramp-compat-funcall 'w32-window-exists-p process-name process-name))
  84
  85      ;; GNU Emacs 23.
  86      ((and (fboundp 'list-system-processes) (fboundp 'process-attributes))
  87       (let (result)
  88         (dolist (pid (tramp-compat-funcall 'list-system-processes) result)
  89           (let ((attributes (process-attributes pid)))
  90             (when (and (string-equal
  91                         (cdr (assoc 'user attributes)) (user-login-name))
  92                        (let ((comm (cdr (assoc 'comm attributes))))
  93                          ;; The returned command name could be truncated
  94                          ;; to 15 characters.  Therefore, we cannot check
  95                          ;; for `string-equal'.
  96                          (and comm (string-match
  97                                     (concat "^" (regexp-quote comm))
  98                                     process-name))))
  99               (setq result t)))))))))
 100
 101 ;; `user-error' has appeared in Emacs 24.3.
 102 (defsubst tramp-compat-user-error (vec-or-proc format &rest args)
 103   "Signal a pilot error."
 104   (apply
 105    'tramp-error vec-or-proc
 106    (if (fboundp 'user-error) 'user-error 'error) format args))
 107
 108 ;; `default-toplevel-value' has been declared in Emacs 24.4.
 109 (unless (fboundp 'default-toplevel-value)
 110   (defalias 'default-toplevel-value 'symbol-value))
 111
 112 ;; `file-attribute-*' are introduced in Emacs 25.1.
 113
 114 (if (fboundp 'file-attribute-type)
 115     (defalias 'tramp-compat-file-attribute-type 'file-attribute-type)
 116   (defsubst tramp-compat-file-attribute-type (attributes)
 117     "The type field in ATTRIBUTES returned by `file-attributes'.
 118 The value is either t for directory, string (name linked to) for
 119 symbolic link, or nil."
 120     (nth 0 attributes)))
 121
 122 (if (fboundp 'file-attribute-link-number)
 123     (defalias 'tramp-compat-file-attribute-link-number
 124       'file-attribute-link-number)
 125   (defsubst tramp-compat-file-attribute-link-number (attributes)
 126     "Return the number of links in ATTRIBUTES returned by `file-attributes'."
 127     (nth 1 attributes)))
 128
 129 (if (fboundp 'file-attribute-user-id)
 130     (defalias 'tramp-compat-file-attribute-user-id 'file-attribute-user-id)
 131   (defsubst tramp-compat-file-attribute-user-id (attributes)
 132     "The UID field in ATTRIBUTES returned by `file-attributes'.
 133 This is either a string or a number.  If a string value cannot be
 134 looked up, a numeric value, either an integer or a float, is
 135 returned."
 136     (nth 2 attributes)))
 137
 138 (if (fboundp 'file-attribute-group-id)
 139     (defalias 'tramp-compat-file-attribute-group-id 'file-attribute-group-id)
 140   (defsubst tramp-compat-file-attribute-group-id (attributes)
 141     "The GID field in ATTRIBUTES returned by `file-attributes'.
 142 This is either a string or a number.  If a string value cannot be
 143 looked up, a numeric value, either an integer or a float, is
 144 returned."
 145     (nth 3 attributes)))
 146
 147 (if (fboundp 'file-attribute-modification-time)
 148     (defalias 'tramp-compat-file-attribute-modification-time
 149       'file-attribute-modification-time)
 150   (defsubst tramp-compat-file-attribute-modification-time (attributes)
 151     "The modification time in ATTRIBUTES returned by `file-attributes'.
 152 This is the time of the last change to the file's contents, and
 153 is a list of integers (HIGH LOW USEC PSEC) in the same style
 154 as (current-time)."
 155     (nth 5 attributes)))
 156
 157 (if (fboundp 'file-attribute-size)
 158     (defalias 'tramp-compat-file-attribute-size 'file-attribute-size)
 159   (defsubst tramp-compat-file-attribute-size (attributes)
 160     "The size (in bytes) in ATTRIBUTES returned by `file-attributes'.
 161 This is a floating point number if the size is too large for an integer."
 162     (nth 7 attributes)))
 163
 164 (if (fboundp 'file-attribute-modes)
 165     (defalias 'tramp-compat-file-attribute-modes 'file-attribute-modes)
 166   (defsubst tramp-compat-file-attribute-modes (attributes)
 167     "The file modes in ATTRIBUTES returned by `file-attributes'.
 168 This is a string of ten letters or dashes as in ls -l."
 169     (nth 8 attributes)))
 170
 171 ;; `format-message' is new in Emacs 25.1.
 172 (unless (fboundp 'format-message)
 173   (defalias 'format-message 'format))
 174
 175 ;; `directory-name-p' is new in Emacs 25.1.
 176 (if (fboundp 'directory-name-p)
 177     (defalias 'tramp-compat-directory-name-p 'directory-name-p)
 178   (defsubst tramp-compat-directory-name-p (name)
 179     "Return non-nil if NAME ends with a directory separator character."
 180     (let ((len (length name))
 181           (lastc ?.))
 182       (if (> len 0)
 183           (setq lastc (aref name (1- len))))
 184       (or (= lastc ?/)
 185           (and (memq system-type '(windows-nt ms-dos))
 186                (= lastc ?\\))))))
 187
 188 ;; `file-missing' is introduced in Emacs 26.1.
 189 (defconst tramp-file-missing
 190   (if (get 'file-missing 'error-conditions) 'file-missing 'file-error)
 191   "The error symbol for the `file-missing' error.")
 192
 193 (add-hook 'tramp-unload-hook
 194           (lambda ()
 195             (unload-feature 'tramp-loaddefs 'force)
 196             (unload-feature 'tramp-compat 'force)))
 197
 198 ;; `file-name-quoted-p', `file-name-quote' and `file-name-unquote' are
 199 ;; introduced in Emacs 26.
 200 (eval-and-compile
 201   (if (fboundp 'file-name-quoted-p)
 202       (defalias 'tramp-compat-file-name-quoted-p 'file-name-quoted-p)
 203     (defsubst tramp-compat-file-name-quoted-p (name)
 204       "Whether NAME is quoted with prefix \"/:\".
 205 If NAME is a remote file name, check the local part of NAME."
 206       (string-match "^/:" (or (file-remote-p name 'localname) name))))
 207
 208   (if (fboundp 'file-name-quote)
 209       (defalias 'tramp-compat-file-name-quote 'file-name-quote)
 210     (defsubst tramp-compat-file-name-quote (name)
 211       "Add the quotation prefix \"/:\" to file NAME.
 212 If NAME is a remote file name, the local part of NAME is quoted."
 213       (if (tramp-compat-file-name-quoted-p name)
 214           name
 215         (concat
 216          (file-remote-p name) "/:" (or (file-remote-p name 'localname) name)))))
 217
 218   (if (fboundp 'file-name-unquote)
 219       (defalias 'tramp-compat-file-name-unquote 'file-name-unquote)
 220     (defsubst tramp-compat-file-name-unquote (name)
 221       "Remove quotation prefix \"/:\" from file NAME.
 222 If NAME is a remote file name, the local part of NAME is unquoted."
 223       (save-match-data
 224         (let ((localname (or (file-remote-p name 'localname) name)))
 225           (when (tramp-compat-file-name-quoted-p localname)
 226             (setq
 227              localname
 228              (replace-match
 229               (if (= (length localname) 2) "/" "") nil t localname)))
 230           (concat (file-remote-p name) localname))))))
 231
 232 ;; `tramp-syntax' has changed its meaning in Emacs 26.  We still
 233 ;; support old settings.
 234 (defsubst tramp-compat-tramp-syntax ()
 235   "Return proper value of `tramp-syntax'."
 236   (cond ((eq tramp-syntax 'ftp) 'default)
 237         ((eq tramp-syntax 'sep) 'separate)
 238         (t tramp-syntax)))
 239
 240 ;; `cl-struct-slot-info' has been introduced with Emacs 25.
 241 (defmacro tramp-compat-tramp-file-name-slots ()
 242   (if (fboundp 'cl-struct-slot-info)
 243       `(cdr (mapcar 'car (cl-struct-slot-info 'tramp-file-name)))
 244     `(cdr (mapcar 'car (get 'tramp-file-name 'cl-struct-slots)))))
 245
 246 (provide 'tramp-compat)
 247
 248 ;;; TODO:
 249
 250 ;;; tramp-compat.el ends here