lisp/eshell/em-dirs.el

   1 ;;; em-dirs.el --- directory navigation commands
   2
   3 ;; Copyright (C) 1999, 2000 Free Software Foundation
   4
   5 ;; Author: John Wiegley <johnw@gnu.org>
   6
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation; either version 2, or (at your option)
  12 ;; any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22 ;; Boston, MA 02111-1307, USA.
  23
  24 (provide 'em-dirs)
  25
  26 (eval-when-compile (require 'esh-maint))
  27
  28 (defgroup eshell-dirs nil
  29   "Directory navigation involves changing directories, examining the
  30 current directory, maintaining a directory stack, and also keeping
  31 track of a history of the last directory locations the user was in.
  32 Emacs does provide standard Lisp definitions of `pwd' and `cd', but
  33 they lack somewhat in feel from the typical shell equivalents."
  34   :tag "Directory navigation"
  35   :group 'eshell-module)
  36
  37 ;;; Commentary:
  38
  39 ;; The only special feature that Eshell offers in the last-dir-ring.
  40 ;; To view the ring, enter:
  41 ;;
  42 ;;   cd =
  43 ;;
  44 ;; Changing to an index within the ring is done using:
  45 ;;
  46 ;;   cd -      ; same as cd -0
  47 ;;   cd -4
  48 ;;
  49 ;; Or, it is possible to change the first member in the ring which
  50 ;; matches a regexp:
  51 ;;
  52 ;;   cd =bcc   ; change to the last directory visited containing "bcc"
  53 ;;
  54 ;; This ring is maintained automatically, and is persisted across
  55 ;; Eshell sessions.  It is a separate mechanism from `pushd' and
  56 ;; `popd', and the two may be used at the same time.
  57
  58 (require 'ring)
  59 (require 'esh-opt)
  60
  61 ;;; User Variables:
  62
  63 (defcustom eshell-dirs-load-hook '(eshell-dirs-initialize)
  64   "*A hook that gets run when `eshell-dirs' is loaded."
  65   :type 'hook
  66   :group 'eshell-dirs)
  67
  68 (defcustom eshell-pwd-convert-function (if (eshell-under-windows-p)
  69                                            'expand-file-name
  70                                          'identity)
  71   "*The function used to normalize the value of Eshell's `pwd'.
  72 The value returned by `pwd' is also used when recording the
  73 last-visited directory in the last-dir-ring, so it will affect the
  74 form of the list used by 'cd ='."
  75   :type '(radio (function-item file-truename)
  76                 (function-item expand-file-name)
  77                 (function-item identity)
  78                 (function :tag "Other"))
  79   :group 'eshell-dirs)
  80
  81 (defcustom eshell-ask-to-save-last-dir 'always
  82   "*Determine if the last-dir-ring should be automatically saved.
  83 The last-dir-ring is always preserved when exiting an Eshell buffer.
  84 However, when Emacs is being shut down, this variable determines
  85 whether to prompt the user, or just save the ring.
  86 If set to nil, it means never ask whether to save the last-dir-ring.
  87 If set to t, always ask if any Eshell buffers are open at exit time.
  88 If set to `always', the list-dir-ring will always be saved, silently."
  89   :type '(choice (const :tag "Never" nil)
  90                  (const :tag "Ask" t)
  91                  (const :tag "Always save" always))
  92   :group 'eshell-dirs)
  93
  94 (defcustom eshell-cd-shows-directory nil
  95   "*If non-nil, using `cd' will report the directory it changes to."
  96   :type 'boolean
  97   :group 'eshell-dirs)
  98
  99 (defcustom eshell-cd-on-directory t
 100   "*If non-nil, do a cd if a directory is in command position."
 101   :type 'boolean
 102   :group 'eshell-dirs)
 103
 104 (defcustom eshell-directory-change-hook nil
 105   "*A hook to run when the current directory changes."
 106   :type 'hook
 107   :group 'eshell-dirs)
 108
 109 (defcustom eshell-list-files-after-cd nil
 110   "*If non-nil, call \"ls\" with any remaining args after doing a cd.
 111 This is provided for convenience, since the same effect is easily
 112 achieved by adding a function to `eshell-directory-change-hook' that
 113 calls \"ls\" and references `eshell-last-arguments'."
 114   :type 'boolean
 115   :group 'eshell-dirs)
 116
 117 (defcustom eshell-pushd-tohome nil
 118   "*If non-nil, make pushd with no arg behave as 'pushd ~' (like `cd').
 119 This mirrors the optional behavior of tcsh."
 120   :type 'boolean
 121   :group 'eshell-dirs)
 122
 123 (defcustom eshell-pushd-dextract nil
 124   "*If non-nil, make \"pushd +n\" pop the nth dir to the stack top.
 125 This mirrors the optional behavior of tcsh."
 126   :type 'boolean
 127   :group 'eshell-dirs)
 128
 129 (defcustom eshell-pushd-dunique nil
 130   "*If non-nil, make pushd only add unique directories to the stack.
 131 This mirrors the optional behavior of tcsh."
 132   :type 'boolean
 133   :group 'eshell-dirs)
 134
 135 (defcustom eshell-dirtrack-verbose t
 136   "*If non-nil, show the directory stack following directory change.
 137 This is effective only if directory tracking is enabled."
 138   :type 'boolean
 139   :group 'eshell-dirs)
 140
 141 (defcustom eshell-last-dir-ring-file-name
 142   (concat eshell-directory-name "lastdir")
 143   "*If non-nil, name of the file to read/write the last-dir-ring.
 144 See also `eshell-read-last-dir-ring' and `eshell-write-last-dir-ring'.
 145 If it is nil, the last-dir-ring will not be written to disk."
 146   :type 'file
 147   :group 'eshell-dirs)
 148
 149 (defcustom eshell-last-dir-ring-size 32
 150   "*If non-nil, the size of the directory history ring.
 151 This ring is added to every time `cd' or `pushd' is used.  It simply
 152 stores the most recent directory locations Eshell has been in.  To
 153 return to the most recent entry, use 'cd -' (equivalent to 'cd -0').
 154 To return to an older entry, use 'cd -N', where N is an integer less
 155 than `eshell-last-dir-ring-size'.  To return to the last directory
 156 matching a particular regexp, use 'cd =REGEXP'.  To display the
 157 directory history list, use 'cd ='.
 158
 159 This mechanism is very similar to that provided by `pushd', except
 160 it's far more automatic.  `pushd' allows the user to decide which
 161 directories gets pushed, and its size is unlimited.
 162
 163 `eshell-last-dir-ring' is meant for users who don't use `pushd'
 164 explicity very much, but every once in a while would like to return to
 165 a previously visited directory without having to type in the whole
 166 thing again."
 167   :type 'integer
 168   :group 'eshell-dirs)
 169
 170 (defcustom eshell-last-dir-unique t
 171   "*If non-nil, `eshell-last-dir-ring' contains only unique entries."
 172   :type 'boolean
 173   :group 'eshell-dirs)
 174
 175 ;;; Internal  Variables:
 176
 177 (defvar eshell-dirstack nil
 178   "List of directories saved by pushd in the Eshell buffer.
 179 Thus, this does not include the current directory.")
 180
 181 (defvar eshell-last-dir-ring nil
 182   "The last directory that eshell was in.")
 183
 184 ;;; Functions:
 185
 186 (defun eshell-dirs-initialize ()
 187   "Initialize the builtin functions for Eshell."
 188   (make-local-variable 'eshell-variable-aliases-list)
 189   (setq eshell-variable-aliases-list
 190         (append
 191          eshell-variable-aliases-list
 192          '(("-" (lambda (indices)
 193                   (if (not indices)
 194                       (unless (ring-empty-p eshell-last-dir-ring)
 195                         (expand-file-name
 196                          (ring-ref eshell-last-dir-ring 0)))
 197                     (expand-file-name
 198                      (eshell-apply-indices eshell-last-dir-ring indices)))))
 199            ("+" "PWD")
 200            ("PWD" (lambda (indices)
 201                     (expand-file-name (eshell/pwd))) t)
 202            ("OLDPWD" (lambda (indices)
 203                        (unless (ring-empty-p eshell-last-dir-ring)
 204                          (expand-file-name
 205                           (ring-ref eshell-last-dir-ring 0)))) t))))
 206
 207   (when eshell-cd-on-directory
 208     (make-local-variable 'eshell-interpreter-alist)
 209     (setq eshell-interpreter-alist
 210           (cons (cons 'eshell-lone-directory-p
 211                       'eshell-dirs-substitute-cd)
 212                 eshell-interpreter-alist)))
 213
 214   (make-local-hook 'eshell-parse-argument-hook)
 215   (add-hook 'eshell-parse-argument-hook
 216             'eshell-parse-user-reference nil t)
 217   (if (eshell-under-windows-p)
 218       (add-hook 'eshell-parse-argument-hook
 219                 'eshell-parse-drive-letter nil t))
 220
 221   (when (eshell-using-module 'eshell-cmpl)
 222     (make-local-hook 'pcomplete-try-first-hook)
 223     (add-hook 'pcomplete-try-first-hook
 224               'eshell-complete-user-reference nil t))
 225
 226   (make-local-variable 'eshell-dirstack)
 227   (make-local-variable 'eshell-last-dir-ring)
 228
 229   (if eshell-last-dir-ring-file-name
 230       (eshell-read-last-dir-ring))
 231   (unless eshell-last-dir-ring
 232     (setq eshell-last-dir-ring (make-ring eshell-last-dir-ring-size)))
 233
 234   (make-local-hook 'eshell-exit-hook)
 235   (add-hook 'eshell-exit-hook 'eshell-write-last-dir-ring nil t)
 236
 237   (add-hook 'kill-emacs-hook 'eshell-save-some-last-dir))
 238
 239 (defun eshell-save-some-last-dir ()
 240   "Save the list-dir-ring for any open Eshell buffers."
 241   (eshell-for buf (buffer-list)
 242     (if (buffer-live-p buf)
 243         (with-current-buffer buf
 244           (if (and eshell-mode
 245                    eshell-ask-to-save-last-dir
 246                    (or (eq eshell-ask-to-save-last-dir 'always)
 247                        (y-or-n-p
 248                         (format "Save last dir ring for Eshell buffer `%s'? "
 249                                 (buffer-name buf)))))
 250               (eshell-write-last-dir-ring))))))
 251
 252 (defun eshell-lone-directory-p (file)
 253   "Test whether FILE is just a directory name, and not a command name."
 254   (and (file-directory-p file)
 255        (or (file-name-directory file)
 256            (not (eshell-search-path file)))))
 257
 258 (defun eshell-dirs-substitute-cd (&rest args)
 259   "Substitute the given command for a call to `cd' on that name."
 260   (if (> (length args) 1)
 261       (error "%s: command not found" (car args))
 262     (throw 'eshell-replace-command
 263            (eshell-parse-command "cd" (eshell-flatten-list args)))))
 264
 265 (defun eshell-parse-user-reference ()
 266   "An argument beginning with ~ is a filename to be expanded."
 267   (when (and (not eshell-current-argument)
 268              (eq (char-after) ?~))
 269     (add-to-list 'eshell-current-modifiers 'expand-file-name)
 270     (forward-char)
 271     (char-to-string (char-before))))
 272
 273 (defun eshell-parse-drive-letter ()
 274   "An argument beginning X:[^/] is a drive letter reference."
 275   (when (and (not eshell-current-argument)
 276              (looking-at "\\([A-Za-z]:\\)\\([^/\\\\]\\|\\'\\)"))
 277     (goto-char (match-end 1))
 278     (let* ((letter (match-string 1))
 279            (regexp (concat "\\`" letter))
 280            (path (eshell-find-previous-directory regexp)))
 281       (concat (or path letter)
 282               (char-to-string directory-sep-char)))))
 283
 284 (defun eshell-complete-user-reference ()
 285   "If there is a user reference, complete it."
 286   (let ((arg (pcomplete-actual-arg)))
 287     (when (string-match "\\`~[a-z]*\\'" arg)
 288       (setq pcomplete-stub (substring arg 1)
 289             pcomplete-last-completion-raw t)
 290       (throw 'pcomplete-completions
 291              (progn
 292                (eshell-read-user-names)
 293                (pcomplete-uniqify-list
 294                 (mapcar
 295                  (function
 296                   (lambda (user)
 297                     (file-name-as-directory (cdr user))))
 298                  eshell-user-names)))))))
 299
 300 (defun eshell/pwd (&rest args)
 301   "Change output from `pwd` to be cleaner."
 302   (let* ((path default-directory)
 303          (len (length path)))
 304     (if (and (> len 1)
 305              (eq (aref path (1- len)) directory-sep-char)
 306              (not (and (eshell-under-windows-p)
 307                        (string-match "\\`[A-Za-z]:[\\\\/]\\'" path))))
 308         (setq path (substring path 0 (1- (length path)))))
 309     (if eshell-pwd-convert-function
 310         (funcall eshell-pwd-convert-function path)
 311       path)))
 312
 313 (defun eshell-expand-multiple-dots (path)
 314   "Convert '...' to '../..', '....' to '../../..', etc..
 315
 316 With the following piece of advice, you can make this functionality
 317 available in most of Emacs, with the exception of filename completion
 318 in the minibuffer:
 319
 320   (defadvice expand-file-name
 321     (before translate-multiple-dots
 322             (filename &optional directory) activate)
 323     (setq filename (eshell-expand-multiple-dots filename)))"
 324   (while (string-match "\\.\\.\\(\\.+\\)" path)
 325     (let* ((extra-dots (match-string 1 path))
 326            (len (length extra-dots))
 327            replace-text)
 328       (while (> len 0)
 329         (setq replace-text
 330               (concat replace-text
 331                       (char-to-string directory-sep-char) "..")
 332               len (1- len)))
 333       (setq path
 334             (replace-match replace-text t t path 1))))
 335   path)
 336
 337 (defun eshell-find-previous-directory (regexp)
 338   "Find the most recent last-dir matching REGEXP."
 339   (let ((index 0)
 340         (len (ring-length eshell-last-dir-ring))
 341         oldpath)
 342     (if (> (length regexp) 0)
 343         (while (< index len)
 344           (setq oldpath (ring-ref eshell-last-dir-ring index))
 345           (if (string-match regexp oldpath)
 346               (setq index len)
 347             (setq oldpath nil
 348                   index (1+ index)))))
 349     oldpath))
 350
 351 (eval-when-compile
 352   (defvar dired-directory))
 353
 354 (defun eshell/cd (&rest args)           ; all but first ignored
 355   "Alias to extend the behavior of `cd'."
 356   (setq args (eshell-flatten-list args))
 357   (let ((path (car args))
 358         (subpath (car (cdr args)))
 359         (case-fold-search (eshell-under-windows-p))
 360         handled)
 361     (if (numberp path)
 362         (setq path (number-to-string path)))
 363     (if (numberp subpath)
 364         (setq subpath (number-to-string subpath)))
 365     (cond
 366      (subpath
 367       (let ((curdir (eshell/pwd)))
 368         (if (string-match path curdir)
 369             (setq path (replace-match subpath nil nil curdir))
 370           (error "Path substring '%s' not found" path))))
 371      ((and path (string-match "^-\\([0-9]*\\)$" path))
 372       (let ((index (match-string 1 path)))
 373         (setq path
 374               (ring-remove eshell-last-dir-ring
 375                            (if index
 376                                (string-to-int index)
 377                              0)))))
 378      ((and path (string-match "^=\\(.*\\)$" path))
 379       (let ((oldpath (eshell-find-previous-directory
 380                       (match-string 1 path))))
 381         (if oldpath
 382             (setq path oldpath)
 383           (let ((len (ring-length eshell-last-dir-ring))
 384                 (index 0))
 385             (if (= len 0)
 386                 (error "Directory ring empty"))
 387             (eshell-init-print-buffer)
 388             (while (< index len)
 389               (eshell-buffered-print
 390                (concat (number-to-string index) ": "
 391                        (ring-ref eshell-last-dir-ring index) "\n"))
 392               (setq index (1+ index)))
 393             (eshell-flush)
 394             (setq handled t)))))
 395      (path
 396       (setq path (eshell-expand-multiple-dots path))))
 397     (unless handled
 398       (setq dired-directory (or path "~"))
 399       (let ((curdir (eshell/pwd)))
 400         (unless (equal curdir dired-directory)
 401           (eshell-add-to-dir-ring curdir))
 402         (let ((result (cd dired-directory)))
 403           (and eshell-cd-shows-directory
 404                (eshell-printn result)))
 405         (run-hooks 'eshell-directory-change-hook)
 406         (if eshell-list-files-after-cd
 407             (throw 'eshell-replace-command
 408                    (eshell-parse-command "ls" (cdr args))))
 409         nil))))
 410
 411 (put 'eshell/cd 'eshell-no-numeric-conversions t)
 412
 413 (defun eshell-add-to-dir-ring (path)
 414   "Add PATH to the last-dir-ring, if applicable."
 415   (unless (and (not (ring-empty-p eshell-last-dir-ring))
 416                (equal path (ring-ref eshell-last-dir-ring 0)))
 417     (if eshell-last-dir-unique
 418         (let ((index 0)
 419               (len (ring-length eshell-last-dir-ring)))
 420           (while (< index len)
 421             (if (equal (ring-ref eshell-last-dir-ring index) path)
 422                 (ring-remove eshell-last-dir-ring index)
 423               (setq index (1+ index))))))
 424     (ring-insert eshell-last-dir-ring path)))
 425
 426 ;;; pushd [+n | dir]
 427 (defun eshell/pushd (&rest args)        ; all but first ignored
 428   "Implementation of pushd in Lisp."
 429   (let ((path (car args)))
 430     (cond
 431      ((null path)
 432       ;; no arg -- swap pwd and car of stack unless eshell-pushd-tohome
 433       (cond (eshell-pushd-tohome
 434              (eshell/pushd "~"))
 435             (eshell-dirstack
 436              (let ((old (eshell/pwd)))
 437                (eshell/cd (car eshell-dirstack))
 438                (setq eshell-dirstack (cons old (cdr eshell-dirstack)))
 439                (eshell/dirs t)))
 440             (t
 441              (error "pushd: No other directory"))))
 442      ((string-match "^\\+\\([0-9]\\)" path)
 443       ;; pushd +n
 444       (setq path (string-to-number (match-string 1 path)))
 445       (cond ((> path (length eshell-dirstack))
 446              (error "Directory stack not that deep"))
 447             ((= path 0)
 448              (error "Couldn't cd"))
 449             (eshell-pushd-dextract
 450              (let ((dir (nth (1- path) eshell-dirstack)))
 451                (eshell/popd path)
 452                (eshell/pushd (eshell/pwd))
 453                (eshell/cd dir)
 454                (eshell/dirs t)))
 455             (t
 456              (let* ((ds (cons (eshell/pwd) eshell-dirstack))
 457                     (dslen (length ds))
 458                     (front (nthcdr path ds))
 459                     (back (nreverse (nthcdr (- dslen path) (reverse ds))))
 460                     (new-ds (append front back)))
 461                (eshell/cd (car new-ds))
 462                (setq eshell-dirstack (cdr new-ds))
 463                (eshell/dirs t)))))
 464      (t
 465       ;; pushd <dir>
 466       (let ((old-wd (eshell/pwd)))
 467         (eshell/cd path)
 468         (if (or (null eshell-pushd-dunique)
 469                 (not (member old-wd eshell-dirstack)))
 470             (setq eshell-dirstack (cons old-wd eshell-dirstack)))
 471         (eshell/dirs t)))))
 472   nil)
 473
 474 (put 'eshell/pushd 'eshell-no-numeric-conversions t)
 475
 476 ;;; popd [+n]
 477 (defun eshell/popd (&rest args)
 478   "Implementation of popd in Lisp."
 479   (let ((ref (or (car args) "+0")))
 480     (unless (and (stringp ref)
 481                  (string-match "\\`\\([+-][0-9]+\\)\\'" ref))
 482       (error "popd: bad arg `%s'" ref))
 483     (setq ref (string-to-number (match-string 1 ref)))
 484     (cond ((= ref 0)
 485            (unless eshell-dirstack
 486              (error "popd: Directory stack empty"))
 487            (eshell/cd (car eshell-dirstack))
 488            (setq eshell-dirstack (cdr eshell-dirstack))
 489            (eshell/dirs t))
 490           ((<= (abs ref) (length eshell-dirstack))
 491            (let* ((ds (cons nil eshell-dirstack))
 492                   (cell (nthcdr (if (> ref 0)
 493                                     (1- ref)
 494                                   (+ (length eshell-dirstack) ref)) ds))
 495                   (dir (cadr cell)))
 496              (eshell/cd dir)
 497              (setcdr cell (cdr (cdr cell)))
 498              (setq eshell-dirstack (cdr ds))
 499              (eshell/dirs t)))
 500           (t
 501            (error "Couldn't popd"))))
 502   nil)
 503
 504 (put 'eshell/popd 'eshell-no-numeric-conversions t)
 505
 506 (defun eshell/dirs (&optional if-verbose)
 507   "Implementation of dirs in Lisp."
 508   (when (or (not if-verbose) eshell-dirtrack-verbose)
 509     (let* ((msg "")
 510            (ds (cons (eshell/pwd) eshell-dirstack))
 511            (home (expand-file-name "~/"))
 512            (homelen (length home)))
 513       (while ds
 514         (let ((dir (car ds)))
 515           (and (>= (length dir) homelen)
 516                (string= home (substring dir 0 homelen))
 517                (setq dir (concat "~/" (substring dir homelen))))
 518           (setq msg (concat msg (directory-file-name dir) " "))
 519           (setq ds (cdr ds))))
 520       msg)))
 521
 522 (defun eshell-read-last-dir-ring ()
 523   "Sets the buffer's `eshell-last-dir-ring' from a history file."
 524   (let ((file eshell-last-dir-ring-file-name))
 525     (cond
 526      ((or (null file)
 527           (equal file "")
 528           (not (file-readable-p file)))
 529       nil)
 530      (t
 531       (let* ((count 0)
 532              (size eshell-last-dir-ring-size)
 533              (ring (make-ring size)))
 534         (with-temp-buffer
 535           (insert-file-contents file)
 536           ;; Save restriction in case file is already visited...
 537           ;; Watch for those date stamps in history files!
 538           (goto-char (point-max))
 539           (while (and (< count size)
 540                       (re-search-backward "^\\([^\n].*\\)$" nil t))
 541             (ring-insert-at-beginning ring (match-string 1))
 542             (setq count (1+ count)))
 543           ;; never allow the top element to equal the current
 544           ;; directory
 545           (while (and (not (ring-empty-p ring))
 546                       (equal (ring-ref ring 0) (eshell/pwd)))
 547             (ring-remove ring 0)))
 548         (setq eshell-last-dir-ring ring))))))
 549
 550 (defun eshell-write-last-dir-ring ()
 551   "Writes the buffer's `eshell-last-dir-ring' to a history file."
 552   (let ((file eshell-last-dir-ring-file-name))
 553     (cond
 554      ((or (null file)
 555           (equal file "")
 556           (null eshell-last-dir-ring)
 557           (ring-empty-p eshell-last-dir-ring))
 558       nil)
 559      ((not (file-writable-p file))
 560       (message "Cannot write last-dir-ring file %s" file))
 561      (t
 562       (let* ((ring eshell-last-dir-ring)
 563              (index (ring-length ring)))
 564         (with-temp-buffer
 565           (while (> index 0)
 566             (setq index (1- index))
 567             (insert (ring-ref ring index) ?\n))
 568           (insert (eshell/pwd) ?\n)
 569           (eshell-with-private-file-modes
 570            (write-region (point-min) (point-max) file nil
 571                          'no-message))))))))
 572
 573 ;;; Code:
 574
 575 ;;; em-dirs.el ends here