lisp/net/tramp-compat.el

   1 ;;; tramp-compat.el --- Tramp compatibility functions
   2
   3 ;; Copyright (C) 2007-2014 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 <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; Tramp's main Emacs version for development is Emacs 24.  This
  27 ;; package provides compatibility functions for Emacs 22, Emacs 23,
  28 ;; XEmacs 21.4+ and SXEmacs 22.
  29
  30 ;;; Code:
  31
  32 ;; Pacify byte-compiler.
  33 (eval-when-compile
  34   (require 'cl))
  35
  36 (eval-and-compile
  37
  38   ;; Some packages must be required for XEmacs, because we compile
  39   ;; with -no-autoloads.
  40   (when (featurep 'xemacs)
  41     (require 'cus-edit)
  42     (require 'env)
  43     (require 'executable)
  44     (require 'outline)
  45     (require 'passwd)
  46     (require 'pp)
  47     (require 'regexp-opt))
  48
  49   (require 'advice)
  50   (require 'custom)
  51   (require 'format-spec)
  52   (require 'shell)
  53
  54   (require 'trampver)
  55   (require 'tramp-loaddefs)
  56
  57   ;; As long as password.el is not part of (X)Emacs, it shouldn't be
  58   ;; mandatory.
  59   (if (featurep 'xemacs)
  60       (load "password" 'noerror)
  61     (or (require 'password-cache nil 'noerror)
  62         (require 'password nil 'noerror))) ; Part of contrib.
  63
  64   ;; auth-source is relatively new.
  65   (if (featurep 'xemacs)
  66       (load "auth-source" 'noerror)
  67     (require 'auth-source nil 'noerror))
  68
  69   ;; Load the appropriate timer package.
  70   (if (featurep 'xemacs)
  71       (require 'timer-funcs)
  72     (require 'timer))
  73
  74   ;; Avoid byte-compiler warnings if the byte-compiler supports this.
  75   ;; Currently, XEmacs supports this.
  76   (when (featurep 'xemacs)
  77     (unless (boundp 'byte-compile-default-warnings)
  78       (defvar byte-compile-default-warnings nil))
  79     (delq 'unused-vars byte-compile-default-warnings))
  80
  81   ;; `last-coding-system-used' is unknown in XEmacs.
  82   (unless (boundp 'last-coding-system-used)
  83     (defvar last-coding-system-used nil))
  84
  85   ;; `directory-sep-char' is an obsolete variable in Emacs.  But it is
  86   ;; used in XEmacs, so we set it here and there.  The following is
  87   ;; needed to pacify Emacs byte-compiler.
  88   ;; Note that it was removed altogether in Emacs 24.1.
  89   (when (boundp 'directory-sep-char)
  90     (defvar byte-compile-not-obsolete-var nil)
  91     (setq byte-compile-not-obsolete-var 'directory-sep-char)
  92     ;; Emacs 23.2.
  93     (defvar byte-compile-not-obsolete-vars nil)
  94     (setq byte-compile-not-obsolete-vars '(directory-sep-char)))
  95
  96   ;; `remote-file-name-inhibit-cache' has been introduced with Emacs 24.1.
  97   ;; Besides `t', `nil', and integer, we use also timestamps (as
  98   ;; returned by `current-time') internally.
  99   (unless (boundp 'remote-file-name-inhibit-cache)
 100     (defvar remote-file-name-inhibit-cache nil))
 101
 102   ;; For not existing functions, or functions with a changed argument
 103   ;; list, there are compiler warnings.  We want to avoid them in
 104   ;; cases we know what we do.
 105   (defmacro tramp-compat-funcall (function &rest arguments)
 106     (if (featurep 'xemacs)
 107         `(funcall (symbol-function ,function) ,@arguments)
 108       `(when (or (subrp ,function) (functionp ,function))
 109          (with-no-warnings (funcall ,function ,@arguments)))))
 110
 111   ;; `set-buffer-multibyte' comes from Emacs Leim.
 112   (unless (fboundp 'set-buffer-multibyte)
 113     (defalias 'set-buffer-multibyte 'ignore))
 114
 115   ;; The following functions cannot be aliases of the corresponding
 116   ;; `tramp-handle-*' functions, because this would bypass the locking
 117   ;; mechanism.
 118
 119   ;; `file-remote-p' has been introduced with Emacs 22.  The version
 120   ;; of XEmacs is not a magic file name function (yet).
 121   (unless (fboundp 'file-remote-p)
 122     (defalias 'file-remote-p
 123       (lambda (file &optional identification connected)
 124         (when (tramp-tramp-file-p file)
 125           (tramp-compat-funcall
 126            'tramp-file-name-handler
 127            'file-remote-p file identification connected)))))
 128
 129   ;; `process-file' does not exist in XEmacs.
 130   (unless (fboundp 'process-file)
 131     (defalias 'process-file
 132       (lambda (program &optional infile buffer display &rest args)
 133         (when (tramp-tramp-file-p default-directory)
 134           (apply
 135            'tramp-file-name-handler
 136            'process-file program infile buffer display args)))))
 137
 138   ;; `start-file-process' is new in Emacs 23.
 139   (unless (fboundp 'start-file-process)
 140     (defalias 'start-file-process
 141       (lambda (name buffer program &rest program-args)
 142         (when (tramp-tramp-file-p default-directory)
 143           (apply
 144            'tramp-file-name-handler
 145            'start-file-process name buffer program program-args)))))
 146
 147   ;; `set-file-times' is also new in Emacs 23.
 148   (unless (fboundp 'set-file-times)
 149     (defalias 'set-file-times
 150       (lambda (filename &optional time)
 151         (when (tramp-tramp-file-p filename)
 152           (tramp-compat-funcall
 153            'tramp-file-name-handler 'set-file-times filename time)))))
 154
 155   ;; We currently use "[" and "]" in the filename format for IPv6
 156   ;; hosts of GNU Emacs.  This means that Emacs wants to expand
 157   ;; wildcards if `find-file-wildcards' is non-nil, and then barfs
 158   ;; because no expansion could be found.  We detect this situation
 159   ;; and do something really awful: we have `file-expand-wildcards'
 160   ;; return the original filename if it can't expand anything.  Let's
 161   ;; just hope that this doesn't break anything else.
 162   ;; It is not needed anymore since GNU Emacs 23.2.
 163   (unless (or (featurep 'xemacs)
 164               ;; `featurep' has only one argument in XEmacs.
 165               (funcall 'featurep 'files 'remote-wildcards))
 166     (defadvice file-expand-wildcards
 167       (around tramp-advice-file-expand-wildcards activate)
 168       (let ((name (ad-get-arg 0)))
 169         ;; If it's a Tramp file, look if wildcards need to be expanded
 170         ;; at all.
 171         (if (and
 172              (tramp-tramp-file-p name)
 173              (not (string-match
 174                    "[[*?]" (tramp-compat-funcall
 175                             'file-remote-p name 'localname))))
 176             (setq ad-return-value (list name))
 177           ;; Otherwise, just run the original function.
 178           ad-do-it)))
 179     (add-hook
 180      'tramp-unload-hook
 181      (lambda ()
 182        (ad-remove-advice
 183         'file-expand-wildcards 'around 'tramp-advice-file-expand-wildcards)
 184        (ad-activate 'file-expand-wildcards)))))
 185
 186 ;; `with-temp-message' does not exist in XEmacs.
 187 (if (fboundp 'with-temp-message)
 188     (defalias 'tramp-compat-with-temp-message 'with-temp-message)
 189   (defmacro tramp-compat-with-temp-message (_message &rest body)
 190     "Display MESSAGE temporarily if non-nil while BODY is evaluated."
 191     `(progn ,@body)))
 192
 193 ;; `condition-case-unless-debug' is introduced with Emacs 24.
 194 (if (fboundp 'condition-case-unless-debug)
 195     (defalias 'tramp-compat-condition-case-unless-debug
 196       'condition-case-unless-debug)
 197   (defmacro tramp-compat-condition-case-unless-debug
 198     (var bodyform &rest handlers)
 199   "Like `condition-case' except that it does not catch anything when debugging."
 200     (declare (debug condition-case) (indent 2))
 201     (let ((bodysym (make-symbol "body")))
 202       `(let ((,bodysym (lambda () ,bodyform)))
 203          (if debug-on-error
 204              (funcall ,bodysym)
 205            (condition-case ,var
 206                (funcall ,bodysym)
 207              ,@handlers))))))
 208
 209 ;; `font-lock-add-keywords' does not exist in XEmacs.
 210 (defun tramp-compat-font-lock-add-keywords (mode keywords &optional how)
 211   "Add highlighting KEYWORDS for MODE."
 212   (ignore-errors
 213     (tramp-compat-funcall 'font-lock-add-keywords mode keywords how)))
 214
 215 (defsubst tramp-compat-temporary-file-directory ()
 216   "Return name of directory for temporary files (compat function).
 217 For Emacs, this is the variable `temporary-file-directory', for XEmacs
 218 this is the function `temp-directory'."
 219   (let (file-name-handler-alist)
 220     ;; We must return a local directory.  If it is remote, we could
 221     ;; run into an infloop.
 222     (cond
 223      ((and (boundp 'temporary-file-directory)
 224            (eval (car (get 'temporary-file-directory 'standard-value)))))
 225      ((fboundp 'temp-directory) (tramp-compat-funcall 'temp-directory))
 226      ((let ((d (getenv "TEMP"))) (and d (file-directory-p d)))
 227       (file-name-as-directory (getenv "TEMP")))
 228      ((let ((d (getenv "TMP"))) (and d (file-directory-p d)))
 229       (file-name-as-directory (getenv "TMP")))
 230      ((let ((d (getenv "TMPDIR"))) (and d (file-directory-p d)))
 231       (file-name-as-directory (getenv "TMPDIR")))
 232      ((file-exists-p "c:/temp") (file-name-as-directory "c:/temp"))
 233      (t (message (concat "Neither `temporary-file-directory' nor "
 234                          "`temp-directory' is defined -- using /tmp."))
 235         (file-name-as-directory "/tmp")))))
 236
 237 ;; `make-temp-file' exists in Emacs only.  On XEmacs, we use our own
 238 ;; implementation with `make-temp-name', creating the temporary file
 239 ;; immediately in order to avoid a security hole.
 240 (defsubst tramp-compat-make-temp-file (f &optional dir-flag)
 241   "Create a temporary file (compat function).
 242 Add the extension of F, if existing."
 243   (let* (file-name-handler-alist
 244          (prefix (expand-file-name
 245                   (symbol-value 'tramp-temp-name-prefix)
 246                   (tramp-compat-temporary-file-directory)))
 247          (extension (file-name-extension f t))
 248          result)
 249     (condition-case nil
 250         (setq result
 251               (tramp-compat-funcall 'make-temp-file prefix dir-flag extension))
 252       (error
 253        ;; We use our own implementation, taken from files.el.
 254        (while
 255            (condition-case ()
 256                (progn
 257                  (setq result (concat (make-temp-name prefix) extension))
 258                  (if dir-flag
 259                      (make-directory result)
 260                    (write-region "" nil result nil 'silent))
 261                  nil)
 262              (file-already-exists t))
 263          ;; The file was somehow created by someone else between
 264          ;; `make-temp-name' and `write-region', let's try again.
 265          nil)))
 266     result))
 267
 268 ;; `most-positive-fixnum' does not exist in XEmacs.
 269 (defsubst tramp-compat-most-positive-fixnum ()
 270   "Return largest positive integer value (compat function)."
 271   (cond
 272    ((boundp 'most-positive-fixnum) (symbol-value 'most-positive-fixnum))
 273    ;; Default value in XEmacs.
 274    (t 134217727)))
 275
 276 (defun tramp-compat-decimal-to-octal (i)
 277   "Return a string consisting of the octal digits of I.
 278 Not actually used.  Use `(format \"%o\" i)' instead?"
 279   (cond ((< i 0) (error "Cannot convert negative number to octal"))
 280         ((not (integerp i)) (error "Cannot convert non-integer to octal"))
 281         ((zerop i) "0")
 282         (t (concat (tramp-compat-decimal-to-octal (/ i 8))
 283                    (number-to-string (% i 8))))))
 284
 285 ;; Kudos to Gerd Moellmann for this suggestion.
 286 (defun tramp-compat-octal-to-decimal (ostr)
 287   "Given a string of octal digits, return a decimal number."
 288   (let ((x (or ostr "")))
 289     ;; `save-match' is in `tramp-mode-string-to-int' which calls this.
 290     (unless (string-match "\\`[0-7]*\\'" x)
 291       (error "Non-octal junk in string `%s'" x))
 292     (string-to-number ostr 8)))
 293
 294 ;; ID-FORMAT does not exist in XEmacs.
 295 (defun tramp-compat-file-attributes (filename &optional id-format)
 296   "Like `file-attributes' for Tramp files (compat function)."
 297   (cond
 298    ((or (null id-format) (eq id-format 'integer))
 299     (file-attributes filename))
 300    ((tramp-tramp-file-p filename)
 301     (tramp-compat-funcall
 302      'tramp-file-name-handler 'file-attributes filename id-format))
 303    (t (condition-case nil
 304           (tramp-compat-funcall 'file-attributes filename id-format)
 305         (wrong-number-of-arguments (file-attributes filename))))))
 306
 307 ;; PRESERVE-UID-GID does not exist in XEmacs.
 308 ;; PRESERVE-EXTENDED-ATTRIBUTES has been introduced with Emacs 24.1
 309 ;; (as PRESERVE-SELINUX-CONTEXT), and renamed in Emacs 24.3.
 310 (defun tramp-compat-copy-file
 311   (filename newname &optional ok-if-already-exists keep-date
 312             preserve-uid-gid preserve-extended-attributes)
 313   "Like `copy-file' for Tramp files (compat function)."
 314   (cond
 315    (preserve-extended-attributes
 316     (condition-case nil
 317         (tramp-compat-funcall
 318          'copy-file filename newname ok-if-already-exists keep-date
 319          preserve-uid-gid preserve-extended-attributes)
 320       (wrong-number-of-arguments
 321        (tramp-compat-copy-file
 322         filename newname ok-if-already-exists keep-date preserve-uid-gid))))
 323    (preserve-uid-gid
 324     (condition-case nil
 325         (tramp-compat-funcall
 326          'copy-file filename newname ok-if-already-exists keep-date
 327          preserve-uid-gid)
 328       (wrong-number-of-arguments
 329        (tramp-compat-copy-file
 330         filename newname ok-if-already-exists keep-date))))
 331    (t
 332     (copy-file filename newname ok-if-already-exists keep-date))))
 333
 334 ;; `copy-directory' is a new function in Emacs 23.2.  Implementation
 335 ;; is taken from there.
 336 (defun tramp-compat-copy-directory
 337   (directory newname &optional keep-time parents copy-contents)
 338   "Make a copy of DIRECTORY (compat function)."
 339   (condition-case nil
 340       (tramp-compat-funcall
 341        'copy-directory directory newname keep-time parents copy-contents)
 342
 343     ;; `copy-directory' is either not implemented, or it does not
 344     ;; support the the COPY-CONTENTS flag.  For the time being, we
 345     ;; ignore COPY-CONTENTS as well.
 346
 347     (error
 348      ;; If `default-directory' is a remote directory, make sure we
 349      ;; find its `copy-directory' handler.
 350      (let ((handler (or (find-file-name-handler directory 'copy-directory)
 351                         (find-file-name-handler newname 'copy-directory))))
 352        (if handler
 353            (funcall handler 'copy-directory directory newname keep-time parents)
 354
 355          ;; Compute target name.
 356          (setq directory (directory-file-name (expand-file-name directory))
 357                newname   (directory-file-name (expand-file-name newname)))
 358          (if (and (file-directory-p newname)
 359                   (not (string-equal (file-name-nondirectory directory)
 360                                      (file-name-nondirectory newname))))
 361              (setq newname
 362                    (expand-file-name
 363                     (file-name-nondirectory directory) newname)))
 364          (if (not (file-directory-p newname)) (make-directory newname parents))
 365
 366          ;; Copy recursively.
 367          (mapc
 368           (lambda (file)
 369             (if (file-directory-p file)
 370                 (tramp-compat-copy-directory file newname keep-time parents)
 371               (copy-file file newname t keep-time)))
 372           ;; We do not want to delete "." and "..".
 373           (directory-files
 374            directory 'full "^\\([^.]\\|\\.\\([^.]\\|\\..\\)\\).*"))
 375
 376          ;; Set directory attributes.
 377          (set-file-modes newname (file-modes directory))
 378          (if keep-time
 379              (set-file-times newname (nth 5 (file-attributes directory)))))))))
 380
 381 ;; TRASH has been introduced with Emacs 24.1.
 382 (defun tramp-compat-delete-file (filename &optional trash)
 383   "Like `delete-file' for Tramp files (compat function)."
 384   (condition-case nil
 385       (tramp-compat-funcall 'delete-file filename trash)
 386     ;; This Emacs version does not support the TRASH flag.
 387     (wrong-number-of-arguments
 388      (let ((delete-by-moving-to-trash
 389             (and (boundp 'delete-by-moving-to-trash)
 390                  (symbol-value 'delete-by-moving-to-trash)
 391                  trash)))
 392        (delete-file filename)))))
 393
 394 ;; RECURSIVE has been introduced with Emacs 23.2.  TRASH has been
 395 ;; introduced with Emacs 24.1.
 396 (defun tramp-compat-delete-directory (directory &optional recursive trash)
 397   "Like `delete-directory' for Tramp files (compat function)."
 398   (condition-case nil
 399       (cond
 400        (trash
 401         (tramp-compat-funcall 'delete-directory directory recursive trash))
 402        (recursive
 403         (tramp-compat-funcall 'delete-directory directory recursive))
 404        (t
 405         (delete-directory directory)))
 406     ;; This Emacs version does not support the RECURSIVE or TRASH flag.  We
 407     ;; use the implementation from Emacs 23.2.
 408     (wrong-number-of-arguments
 409      (setq directory (directory-file-name (expand-file-name directory)))
 410      (if (not (file-symlink-p directory))
 411          (mapc (lambda (file)
 412                  (if (eq t (car (file-attributes file)))
 413                      (tramp-compat-delete-directory file recursive trash)
 414                    (tramp-compat-delete-file file trash)))
 415                (directory-files
 416                 directory 'full "^\\([^.]\\|\\.\\([^.]\\|\\..\\)\\).*")))
 417      (delete-directory directory))))
 418
 419 ;; MUST-SUFFIX doesn't exist on XEmacs.
 420 (defun tramp-compat-load (file &optional noerror nomessage nosuffix must-suffix)
 421   "Like `load' for Tramp files (compat function)."
 422   (if must-suffix
 423       (tramp-compat-funcall 'load file noerror nomessage nosuffix must-suffix)
 424     (load file noerror nomessage nosuffix)))
 425
 426 ;; `number-sequence' does not exist in XEmacs.  Implementation is
 427 ;; taken from Emacs 23.
 428 (defun tramp-compat-number-sequence (from &optional to inc)
 429   "Return a sequence of numbers from FROM to TO as a list (compat function)."
 430   (if (or (subrp 'number-sequence) (symbol-file 'number-sequence))
 431       (tramp-compat-funcall 'number-sequence from to inc)
 432     (if (or (not to) (= from to))
 433         (list from)
 434       (or inc (setq inc 1))
 435       (when (zerop inc) (error "The increment can not be zero"))
 436       (let (seq (n 0) (next from))
 437         (if (> inc 0)
 438             (while (<= next to)
 439               (setq seq (cons next seq)
 440                     n (1+ n)
 441                     next (+ from (* n inc))))
 442           (while (>= next to)
 443             (setq seq (cons next seq)
 444                   n (1+ n)
 445                   next (+ from (* n inc)))))
 446         (nreverse seq)))))
 447
 448 (defun tramp-compat-split-string (string pattern)
 449   "Like `split-string' but omit empty strings.
 450 In Emacs, (split-string \"/foo/bar\" \"/\") returns (\"foo\" \"bar\").
 451 This is, the first, empty, element is omitted.  In XEmacs, the first
 452 element is not omitted."
 453   (delete "" (split-string string pattern)))
 454
 455 (defun tramp-compat-process-running-p (process-name)
 456   "Returns `t' if system process PROCESS-NAME is running for `user-login-name'."
 457   (when (stringp process-name)
 458     (cond
 459      ;; GNU Emacs 22 on w32.
 460      ((fboundp 'w32-window-exists-p)
 461       (tramp-compat-funcall 'w32-window-exists-p process-name process-name))
 462
 463      ;; GNU Emacs 23.
 464      ((and (fboundp 'list-system-processes) (fboundp 'process-attributes))
 465       (let (result)
 466         (dolist (pid (tramp-compat-funcall 'list-system-processes) result)
 467           (let ((attributes (tramp-compat-funcall 'process-attributes pid)))
 468             (when (and (string-equal
 469                         (cdr (assoc 'user attributes)) (user-login-name))
 470                        (let ((comm (cdr (assoc 'comm attributes))))
 471                          ;; The returned command name could be truncated
 472                          ;; to 15 characters.  Therefore, we cannot check
 473                          ;; for `string-equal'.
 474                          (and comm (string-match
 475                                     (concat "^" (regexp-quote comm))
 476                                     process-name))))
 477               (setq result t))))))
 478
 479      ;; Fallback, if there is no Lisp support yet.
 480      (t (let ((default-directory
 481                 (if (tramp-tramp-file-p default-directory)
 482                     (tramp-compat-temporary-file-directory)
 483                   default-directory))
 484               (unix95 (getenv "UNIX95"))
 485               result)
 486           (setenv "UNIX95" "1")
 487           (when (member
 488                  (user-login-name)
 489                  (tramp-compat-split-string
 490                   (shell-command-to-string
 491                    (format "ps -C %s -o user=" process-name))
 492                   "[ \f\t\n\r\v]+"))
 493             (setq result t))
 494           (setenv "UNIX95" unix95)
 495           result)))))
 496
 497 ;; The following functions do not exist in XEmacs.  We ignore this;
 498 ;; they are used for checking a remote tty.
 499 (defun tramp-compat-process-get (process propname)
 500   "Return the value of PROCESS' PROPNAME property.
 501 This is the last value stored with `(process-put PROCESS PROPNAME VALUE)'."
 502   (ignore-errors (tramp-compat-funcall 'process-get process propname)))
 503
 504 (defun tramp-compat-process-put (process propname value)
 505   "Change PROCESS' PROPNAME property to VALUE.
 506 It can be retrieved with `(process-get PROCESS PROPNAME)'."
 507   (ignore-errors (tramp-compat-funcall 'process-put process propname value)))
 508
 509 (defun tramp-compat-set-process-query-on-exit-flag (process flag)
 510   "Specify if query is needed for process when Emacs is exited.
 511 If the second argument flag is non-nil, Emacs will query the user before
 512 exiting if process is running."
 513   (if (fboundp 'set-process-query-on-exit-flag)
 514       (tramp-compat-funcall 'set-process-query-on-exit-flag process flag)
 515     (tramp-compat-funcall 'process-kill-without-query process flag)))
 516
 517 ;; There exist different implementations for this function.
 518 (defun tramp-compat-coding-system-change-eol-conversion (coding-system eol-type)
 519   "Return a coding system like CODING-SYSTEM but with given EOL-TYPE.
 520 EOL-TYPE can be one of `dos', `unix', or `mac'."
 521   (cond ((fboundp 'coding-system-change-eol-conversion)
 522          (tramp-compat-funcall
 523           'coding-system-change-eol-conversion coding-system eol-type))
 524         ((fboundp 'subsidiary-coding-system)
 525          (tramp-compat-funcall
 526           'subsidiary-coding-system coding-system
 527           (cond ((eq eol-type 'dos) 'crlf)
 528                 ((eq eol-type 'unix) 'lf)
 529                 ((eq eol-type 'mac) 'cr)
 530                 (t
 531                  (error "Unknown EOL-TYPE `%s', must be %s"
 532                         eol-type
 533                         "`dos', `unix', or `mac'")))))
 534         (t (error "Can't change EOL conversion -- is MULE missing?"))))
 535
 536 ;; `replace-regexp-in-string' does not exist in XEmacs.
 537 ;; Implementation is taken from Emacs 24.
 538 (if (fboundp 'replace-regexp-in-string)
 539     (defalias 'tramp-compat-replace-regexp-in-string 'replace-regexp-in-string)
 540   (defun tramp-compat-replace-regexp-in-string
 541     (regexp rep string &optional fixedcase literal subexp start)
 542     "Replace all matches for REGEXP with REP in STRING.
 543
 544 Return a new string containing the replacements.
 545
 546 Optional arguments FIXEDCASE, LITERAL and SUBEXP are like the
 547 arguments with the same names of function `replace-match'.  If START
 548 is non-nil, start replacements at that index in STRING.
 549
 550 REP is either a string used as the NEWTEXT arg of `replace-match' or a
 551 function.  If it is a function, it is called with the actual text of each
 552 match, and its value is used as the replacement text.  When REP is called,
 553 the match data are the result of matching REGEXP against a substring
 554 of STRING.
 555
 556 To replace only the first match (if any), make REGEXP match up to \\'
 557 and replace a sub-expression, e.g.
 558   (replace-regexp-in-string \"\\\\(foo\\\\).*\\\\'\" \"bar\" \" foo foo\" nil nil 1)
 559     => \" bar foo\""
 560
 561     (let ((l (length string))
 562           (start (or start 0))
 563           matches str mb me)
 564       (save-match-data
 565         (while (and (< start l) (string-match regexp string start))
 566           (setq mb (match-beginning 0)
 567                 me (match-end 0))
 568           ;; If we matched the empty string, make sure we advance by one char
 569           (when (= me mb) (setq me (min l (1+ mb))))
 570           ;; Generate a replacement for the matched substring.
 571           ;; Operate only on the substring to minimize string consing.
 572           ;; Set up match data for the substring for replacement;
 573           ;; presumably this is likely to be faster than munging the
 574           ;; match data directly in Lisp.
 575           (string-match regexp (setq str (substring string mb me)))
 576           (setq matches
 577                 (cons (replace-match (if (stringp rep)
 578                                          rep
 579                                        (funcall rep (match-string 0 str)))
 580                                      fixedcase literal str subexp)
 581                       (cons (substring string start mb) ; unmatched prefix
 582                             matches)))
 583           (setq start me))
 584         ;; Reconstruct a string from the pieces.
 585         (setq matches (cons (substring string start l) matches)) ; leftover
 586         (apply #'concat (nreverse matches))))))
 587
 588 (add-hook 'tramp-unload-hook
 589           (lambda ()
 590             (unload-feature 'tramp-compat 'force)))
 591
 592 (provide 'tramp-compat)
 593
 594 ;;; TODO:
 595
 596 ;;; tramp-compat.el ends here