summaryrefslogtreecommitdiff
path: root/lisp/net/tramp-compat.el
blob: b8a2b451360fb24e2fbe23f00828cce6f17b938c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
;;; tramp-compat.el --- Tramp compatibility functions  -*- lexical-binding:t -*-

;; Copyright (C) 2007-2019 Free Software Foundation, Inc.

;; Author: Michael Albinus <michael.albinus@gmx.de>
;; Keywords: comm, processes
;; Package: tramp

;; 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:

;; Tramp's main Emacs version for development is Emacs 27.  This
;; package provides compatibility functions for Emacs 24, Emacs 25 and
;; Emacs 26.

;;; Code:

;; In Emacs 24 and 25, `tramp-unload-file-name-handlers' is not
;; autoloaded.  So we declare it here in order to avoid recursive
;; load.  This will be overwritten in tramp.el.
(defun tramp-unload-file-name-handlers ())

(require 'auth-source)
(require 'advice)
(require 'cl-lib)
(require 'custom)
(require 'format-spec)
(require 'parse-time)
(require 'password-cache)
(require 'shell)
(require 'timer)
(require 'ucs-normalize)

(declare-function tramp-compat-file-local-name "tramp-compat")
(declare-function tramp-compat-file-name-quoted-p "tramp-compat")

;; For not existing functions, obsolete functions, or functions with a
;; changed argument list, there are compiler warnings.  We want to
;; avoid them in cases we know what we do.
(defmacro tramp-compat-funcall (function &rest arguments)
  "Call FUNCTION if it exists.  Do not raise compiler warnings."
  `(when (functionp ,function)
     (with-no-warnings (funcall ,function ,@arguments))))

(defsubst tramp-compat-temporary-file-directory ()
  "Return name of directory for temporary files.
It is the default value of `temporary-file-directory'."
  ;; We must return a local directory.  If it is remote, we could run
  ;; into an infloop.
  (eval (car (get 'temporary-file-directory 'standard-value))))

(defsubst tramp-compat-make-temp-file (f &optional dir-flag)
  "Create a local temporary file (compat function).
Add the extension of F, if existing."
  (let* (file-name-handler-alist
	 (prefix (expand-file-name
		  (symbol-value 'tramp-temp-name-prefix)
		  (tramp-compat-temporary-file-directory)))
	 (extension (file-name-extension f t)))
    (make-temp-file prefix dir-flag extension)))

;; `temporary-file-directory' as function is introduced with Emacs 26.1.
(defalias 'tramp-compat-temporary-file-directory-function
  (if (fboundp 'temporary-file-directory)
      #'temporary-file-directory
    'tramp-handle-temporary-file-directory))

(defun tramp-compat-process-running-p (process-name)
  "Returns t if system process PROCESS-NAME is running for `user-login-name'."
  (when (stringp process-name)
    (cond
     ;; GNU Emacs 22 on w32.
     ((fboundp 'w32-window-exists-p)
      (tramp-compat-funcall 'w32-window-exists-p process-name process-name))

     ;; GNU Emacs 23.
     ((and (fboundp 'list-system-processes) (fboundp 'process-attributes))
      (let (result)
	(dolist (pid (tramp-compat-funcall 'list-system-processes) result)
	  (let ((attributes (process-attributes pid)))
	    (when (and (string-equal
                        (cdr (assoc 'user attributes)) (user-login-name))
                       (let ((comm (cdr (assoc 'comm attributes))))
                         ;; The returned command name could be truncated
                         ;; to 15 characters.  Therefore, we cannot check
                         ;; for `string-equal'.
                         (and comm (string-match-p
                                    (concat "^" (regexp-quote comm))
                                    process-name))))
	      (setq result t)))))))))

;; `default-toplevel-value' has been declared in Emacs 24.4.
(unless (fboundp 'default-toplevel-value)
  (defalias 'default-toplevel-value #'symbol-value))

;; `file-attribute-*' are introduced in Emacs 25.1.

(if (fboundp 'file-attribute-type)
    (defalias 'tramp-compat-file-attribute-type #'file-attribute-type)
  (defsubst tramp-compat-file-attribute-type (attributes)
    "The type field in ATTRIBUTES returned by `file-attributes'.
The value is either t for directory, string (name linked to) for
symbolic link, or nil."
    (nth 0 attributes)))

(if (fboundp 'file-attribute-link-number)
    (defalias 'tramp-compat-file-attribute-link-number
      #'file-attribute-link-number)
  (defsubst tramp-compat-file-attribute-link-number (attributes)
    "Return the number of links in ATTRIBUTES returned by `file-attributes'."
    (nth 1 attributes)))

(if (fboundp 'file-attribute-user-id)
    (defalias 'tramp-compat-file-attribute-user-id #'file-attribute-user-id)
  (defsubst tramp-compat-file-attribute-user-id (attributes)
    "The UID field in ATTRIBUTES returned by `file-attributes'.
This is either a string or a number.  If a string value cannot be
looked up, a numeric value, either an integer or a float, is
returned."
    (nth 2 attributes)))

(if (fboundp 'file-attribute-group-id)
    (defalias 'tramp-compat-file-attribute-group-id #'file-attribute-group-id)
  (defsubst tramp-compat-file-attribute-group-id (attributes)
    "The GID field in ATTRIBUTES returned by `file-attributes'.
This is either a string or a number.  If a string value cannot be
looked up, a numeric value, either an integer or a float, is
returned."
    (nth 3 attributes)))

(if (fboundp 'file-attribute-modification-time)
    (defalias 'tramp-compat-file-attribute-modification-time
      #'file-attribute-modification-time)
  (defsubst tramp-compat-file-attribute-modification-time (attributes)
    "The modification time in ATTRIBUTES returned by `file-attributes'.
This is the time of the last change to the file's contents, and
is a Lisp timestamp in the style of `current-time'."
    (nth 5 attributes)))

(if (fboundp 'file-attribute-size)
    (defalias 'tramp-compat-file-attribute-size #'file-attribute-size)
  (defsubst tramp-compat-file-attribute-size (attributes)
    "The size (in bytes) in ATTRIBUTES returned by `file-attributes'.
If the size is too large for a fixnum, this is a bignum in Emacs 27
and later, and is a float in Emacs 26 and earlier."
    (nth 7 attributes)))

(if (fboundp 'file-attribute-modes)
    (defalias 'tramp-compat-file-attribute-modes #'file-attribute-modes)
  (defsubst tramp-compat-file-attribute-modes (attributes)
    "The file modes in ATTRIBUTES returned by `file-attributes'.
This is a string of ten letters or dashes as in ls -l."
    (nth 8 attributes)))

;; `format-message' is new in Emacs 25.1.
(unless (fboundp 'format-message)
  (defalias 'format-message #'format))

;; `directory-name-p' is new in Emacs 25.1.
(if (fboundp 'directory-name-p)
    (defalias 'tramp-compat-directory-name-p #'directory-name-p)
  (defsubst tramp-compat-directory-name-p (name)
    "Return non-nil if NAME ends with a directory separator character."
    (let ((len (length name))
          (lastc ?.))
      (if (> len 0)
          (setq lastc (aref name (1- len))))
      (or (= lastc ?/)
          (and (memq system-type '(windows-nt ms-dos))
               (= lastc ?\\))))))

;; `file-missing' is introduced in Emacs 26.1.
(defconst tramp-file-missing
  (if (get 'file-missing 'error-conditions) 'file-missing 'file-error)
  "The error symbol for the `file-missing' error.")

;; `file-local-name', `file-name-quoted-p', `file-name-quote' and
;; `file-name-unquote' are introduced in Emacs 26.
(if (fboundp 'file-local-name)
    (defalias 'tramp-compat-file-local-name #'file-local-name)
  (defsubst tramp-compat-file-local-name (name)
    "Return the local name component of NAME.
It returns a file name which can be used directly as argument of
`process-file', `start-file-process', or `shell-command'."
    (or (file-remote-p name 'localname) name)))

;; `file-name-quoted-p' got a second argument in Emacs 27.1.
(if (and
     (fboundp 'file-name-quoted-p)
     (equal (tramp-compat-funcall 'func-arity #'file-name-quoted-p) '(1 . 2)))
    (defalias 'tramp-compat-file-name-quoted-p #'file-name-quoted-p)
  (defsubst tramp-compat-file-name-quoted-p (name &optional top)
    "Whether NAME is quoted with prefix \"/:\".
If NAME is a remote file name and TOP is nil, check the local part of NAME."
    (let ((file-name-handler-alist (unless top file-name-handler-alist)))
      (string-prefix-p "/:" (tramp-compat-file-local-name name)))))

(if (fboundp 'file-name-quote)
    (defalias 'tramp-compat-file-name-quote #'file-name-quote)
  (defsubst tramp-compat-file-name-quote (name)
    "Add the quotation prefix \"/:\" to file NAME.
If NAME is a remote file name, the local part of NAME is quoted."
    (if (tramp-compat-file-name-quoted-p name)
	name
      (concat
       (file-remote-p name) "/:" (tramp-compat-file-local-name name)))))

(if (fboundp 'file-name-unquote)
    (defalias 'tramp-compat-file-name-unquote #'file-name-unquote)
  (defsubst tramp-compat-file-name-unquote (name)
    "Remove quotation prefix \"/:\" from file NAME.
If NAME is a remote file name, the local part of NAME is unquoted."
    (let ((localname (tramp-compat-file-local-name name)))
      (when (tramp-compat-file-name-quoted-p localname)
	(setq
	 localname (if (= (length localname) 2) "/" (substring localname 2))))
      (concat (file-remote-p name) localname))))

;; `tramp-syntax' has changed its meaning in Emacs 26.  We still
;; support old settings.
(defsubst tramp-compat-tramp-syntax ()
  "Return proper value of `tramp-syntax'."
  (defvar tramp-syntax)
  (cond ((eq tramp-syntax 'ftp) 'default)
	((eq tramp-syntax 'sep) 'separate)
	(t tramp-syntax)))

;; `cl-struct-slot-info' has been introduced with Emacs 25.
(defmacro tramp-compat-tramp-file-name-slots ()
  (if (fboundp 'cl-struct-slot-info)
      '(cdr (mapcar #'car (cl-struct-slot-info 'tramp-file-name)))
    '(cdr (mapcar #'car (get 'tramp-file-name 'cl-struct-slots)))))

;; The signature of `tramp-make-tramp-file-name' has been changed.
;; Therefore, we cannot use `url-tramp-convert-url-to-tramp' prior
;; Emacs 26.1.  We use `temporary-file-directory' as indicator.
(defconst tramp-compat-use-url-tramp-p (fboundp 'temporary-file-directory)
  "Whether to use url-tramp.el.")

;; `exec-path' is new in Emacs 27.1.
(eval-and-compile
  (if (fboundp 'exec-path)
      (defalias 'tramp-compat-exec-path #'exec-path)
    (defun tramp-compat-exec-path ()
      "List of directories to search programs to run in remote subprocesses."
      (let ((handler (find-file-name-handler default-directory 'exec-path)))
	(if handler
	    (funcall handler 'exec-path)
	  exec-path)))))

;; `time-equal-p' has appeared in Emacs 27.1.
(if (fboundp 'time-equal-p)
    (defalias 'tramp-compat-time-equal-p #'time-equal-p)
  (defsubst tramp-compat-time-equal-p (t1 t2)
    "Return non-nil if time value T1 is equal to time value T2.
A nil value for either argument stands for the current time."
    (equal (or t1 (current-time)) (or t2 (current-time)))))

;; `flatten-tree' has appeared in Emacs 27.1.
(if (fboundp 'flatten-tree)
    (defalias 'tramp-compat-flatten-tree #'flatten-tree)
  (defun tramp-compat-flatten-tree (tree)
    "Take TREE and \"flatten\" it."
    (let (elems)
      (setq tree (list tree))
      (while (let ((elem (pop tree)))
               (cond ((consp elem)
                      (setq tree (cons (car elem) (cons (cdr elem) tree))))
                     (elem
                      (push elem elems)))
               tree))
      (nreverse elems))))

(add-hook 'tramp-unload-hook
	  (lambda ()
	    (unload-feature 'tramp-loaddefs 'force)
	    (unload-feature 'tramp-compat 'force)))

(provide 'tramp-compat)

;;; TODO:

;; * When we get rid of Emacs 24, replace "(mapconcat #'identity" by
;;   "(string-join".

;;; tramp-compat.el ends here