lisp/eshell/em-dirs.el

   1 ;;; em-dirs.el --- directory navigation commands
   2
   3 ;; Copyright (C) 1999, 2000, 2002, 2003, 2004,
   4 ;;   2005, 2006 Free Software Foundation, Inc.
   5
   6 ;; Author: John Wiegley <johnw@gnu.org>
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23 ;; Boston, MA 02110-1301, USA.
  24
  25 (provide 'em-dirs)
  26
  27 (eval-when-compile (require 'esh-maint))
  28 (require 'eshell)
  29
  30 (defgroup eshell-dirs nil
  31   "Directory navigation involves changing directories, examining the
  32 current directory, maintaining a directory stack, and also keeping
  33 track of a history of the last directory locations the user was in.
  34 Emacs does provide standard Lisp definitions of `pwd' and `cd', but
  35 they lack somewhat in feel from the typical shell equivalents."
  36   :tag "Directory navigation"
  37   :group 'eshell-module)
  38
  39 ;;; Commentary:
  40
  41 ;; The only special feature that Eshell offers in the last-dir-ring.
  42 ;; To view the ring, enter:
  43 ;;
  44 ;;   cd =
  45 ;;
  46 ;; Changing to an index within the ring is done using:
  47 ;;
  48 ;;   cd -      ; same as cd -0
  49 ;;   cd -4
  50 ;;
  51 ;; Or, it is possible to change the first member in the ring which
  52 ;; matches a regexp:
  53 ;;
  54 ;;   cd =bcc   ; change to the last directory visited containing "bcc"
  55 ;;
  56 ;; This ring is maintained automatically, and is persisted across
  57 ;; Eshell sessions.  It is a separate mechanism from `pushd' and
  58 ;; `popd', and the two may be used at the same time.
  59
  60 (require 'ring)
  61 (require 'esh-opt)
  62
  63 ;;; User Variables:
  64
  65 (defcustom eshell-dirs-load-hook '(eshell-dirs-initialize)
  66   "*A hook that gets run when `eshell-dirs' is loaded."
  67   :type 'hook
  68   :group 'eshell-dirs)
  69
  70 (defcustom eshell-pwd-convert-function (if (eshell-under-windows-p)
  71                                            'expand-file-name
  72                                          'identity)
  73   "*The function used to normalize the value of Eshell's `pwd'.
  74 The value returned by `pwd' is also used when recording the
  75 last-visited directory in the last-dir-ring, so it will affect the
  76 form of the list used by 'cd ='."
  77   :type '(radio (function-item file-truename)
  78                 (function-item expand-file-name)
  79                 (function-item identity)
  80                 (function :tag "Other"))
  81   :group 'eshell-dirs)
  82
  83 (defcustom eshell-ask-to-save-last-dir 'always
  84   "*Determine if the last-dir-ring should be automatically saved.
  85 The last-dir-ring is always preserved when exiting an Eshell buffer.
  86 However, when Emacs is being shut down, this variable determines
  87 whether to prompt the user, or just save the ring.
  88 If set to nil, it means never ask whether to save the last-dir-ring.
  89 If set to t, always ask if any Eshell buffers are open at exit time.
  90 If set to `always', the list-dir-ring will always be saved, silently."
  91   :type '(choice (const :tag "Never" nil)
  92                  (const :tag "Ask" t)
  93                  (const :tag "Always save" always))
  94   :group 'eshell-dirs)
  95
  96 (defcustom eshell-cd-shows-directory nil
  97   "*If non-nil, using `cd' will report the directory it changes to."
  98   :type 'boolean
  99   :group 'eshell-dirs)
 100
 101 (defcustom eshell-cd-on-directory t
 102   "*If non-nil, do a cd if a directory is in command position."
 103   :type 'boolean
 104   :group 'eshell-dirs)
 105
 106 (defcustom eshell-directory-change-hook nil
 107   "*A hook to run when the current directory changes."
 108   :type 'hook
 109   :group 'eshell-dirs)
 110
 111 (defcustom eshell-list-files-after-cd nil
 112   "*If non-nil, call \"ls\" with any remaining args after doing a cd.
 113 This is provided for convenience, since the same effect is easily
 114 achieved by adding a function to `eshell-directory-change-hook' that
 115 calls \"ls\" and references `eshell-last-arguments'."
 116   :type 'boolean
 117   :group 'eshell-dirs)
 118
 119 (defcustom eshell-pushd-tohome nil
 120   "*If non-nil, make pushd with no arg behave as 'pushd ~' (like `cd').
 121 This mirrors the optional behavior of tcsh."
 122   :type 'boolean
 123   :group 'eshell-dirs)
 124
 125 (defcustom eshell-pushd-dextract nil
 126   "*If non-nil, make \"pushd +n\" pop the nth dir to the stack top.
 127 This mirrors the optional behavior of tcsh."
 128   :type 'boolean
 129   :group 'eshell-dirs)
 130
 131 (defcustom eshell-pushd-dunique nil
 132   "*If non-nil, make pushd only add unique directories to the stack.
 133 This mirrors the optional behavior of tcsh."
 134   :type 'boolean
 135   :group 'eshell-dirs)
 136
 137 (defcustom eshell-dirtrack-verbose t
 138   "*If non-nil, show the directory stack following directory change.
 139 This is effective only if directory tracking is enabled."
 140   :type 'boolean
 141   :group 'eshell-dirs)
 142
 143 (defcustom eshell-last-dir-ring-file-name
 144   (concat eshell-directory-name "lastdir")
 145   "*If non-nil, name of the file to read/write the last-dir-ring.
 146 See also `eshell-read-last-dir-ring' and `eshell-write-last-dir-ring'.
 147 If it is nil, the last-dir-ring will not be written to disk."
 148   :type 'file
 149   :group 'eshell-dirs)
 150
 151 (defcustom eshell-last-dir-ring-size 32
 152   "*If non-nil, the size of the directory history ring.
 153 This ring is added to every time `cd' or `pushd' is used.  It simply
 154 stores the most recent directory locations Eshell has been in.  To
 155 return to the most recent entry, use 'cd -' (equivalent to 'cd -0').
 156 To return to an older entry, use 'cd -N', where N is an integer less
 157 than `eshell-last-dir-ring-size'.  To return to the last directory
 158 matching a particular regexp, use 'cd =REGEXP'.  To display the
 159 directory history list, use 'cd ='.
 160
 161 This mechanism is very similar to that provided by `pushd', except
 162 it's far more automatic.  `pushd' allows the user to decide which
 163 directories gets pushed, and its size is unlimited.
 164
 165 `eshell-last-dir-ring' is meant for users who don't use `pushd'
 166 explicity very much, but every once in a while would like to return to
 167 a previously visited directory without having to type in the whole
 168 thing again."
 169   :type 'integer
 170   :group 'eshell-dirs)
 171
 172 (defcustom eshell-last-dir-unique t
 173   "*If non-nil, `eshell-last-dir-ring' contains only unique entries."
 174   :type 'boolean
 175   :group 'eshell-dirs)
 176
 177 ;;; Internal Variables:
 178
 179 (defvar eshell-dirstack nil
 180   "List of directories saved by pushd in the Eshell buffer.
 181 Thus, this does not include the current directory.")
 182
 183 (defvar eshell-last-dir-ring nil
 184   "The last directory that eshell was in.")
 185
 186 ;;; Functions:
 187
 188 (defun eshell-dirs-initialize ()
 189   "Initialize the builtin functions for Eshell."
 190   (make-local-variable 'eshell-variable-aliases-list)
 191   (setq eshell-variable-aliases-list
 192         (append
 193          eshell-variable-aliases-list
 194          '(("-" (lambda (indices)
 195                   (if (not indices)
 196                       (unless (ring-empty-p eshell-last-dir-ring)
 197                         (expand-file-name
 198                          (ring-ref eshell-last-dir-ring 0)))
 199                     (expand-file-name
 200                      (eshell-apply-indices eshell-last-dir-ring indices)))))
 201            ("+" "PWD")
 202            ("PWD" (lambda (indices)
 203                     (expand-file-name (eshell/pwd))) t)
 204            ("OLDPWD" (lambda (indices)
 205                        (unless (ring-empty-p eshell-last-dir-ring)
 206                          (expand-file-name
 207                           (ring-ref eshell-last-dir-ring 0)))) t))))
 208
 209   (when eshell-cd-on-directory
 210     (make-local-variable 'eshell-interpreter-alist)
 211     (setq eshell-interpreter-alist
 212           (cons (cons 'eshell-lone-directory-p
 213                       'eshell-dirs-substitute-cd)
 214                 eshell-interpreter-alist)))
 215
 216   (add-hook 'eshell-parse-argument-hook
 217             'eshell-parse-user-reference nil t)
 218   (if (eshell-under-windows-p)
 219       (add-hook 'eshell-parse-argument-hook
 220                 'eshell-parse-drive-letter nil t))
 221
 222   (when (eshell-using-module 'eshell-cmpl)
 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   (add-hook 'eshell-exit-hook 'eshell-write-last-dir-ring nil t)
 235
 236   (add-hook 'kill-emacs-hook 'eshell-save-some-last-dir))
 237
 238 (defun eshell-save-some-last-dir ()
 239   "Save the list-dir-ring for any open Eshell buffers."
 240   (eshell-for buf (buffer-list)
 241     (if (buffer-live-p buf)
 242         (with-current-buffer buf
 243           (if (and eshell-mode
 244                    eshell-ask-to-save-last-dir
 245                    (or (eq eshell-ask-to-save-last-dir 'always)
 246                        (y-or-n-p
 247                         (format "Save last dir ring for Eshell buffer `%s'? "
 248                                 (buffer-name buf)))))
 249               (eshell-write-last-dir-ring))))))
 250
 251 (defun eshell-lone-directory-p (file)
 252   "Test whether FILE is just a directory name, and not a command name."
 253   (and (file-directory-p file)
 254        (or (file-name-directory file)
 255            (not (eshell-search-path file)))))
 256
 257 (defun eshell-dirs-substitute-cd (&rest args)
 258   "Substitute the given command for a call to `cd' on that name."
 259   (if (> (length args) 1)
 260       (error "%s: command not found" (car args))
 261     (throw 'eshell-replace-command
 262            (eshell-parse-command "cd" (eshell-flatten-list args)))))
 263
 264 (defun eshell-parse-user-reference ()
 265   "An argument beginning with ~ is a filename to be expanded."
 266   (when (and (not eshell-current-argument)
 267              (eq (char-after) ?~))
 268     (add-to-list 'eshell-current-modifiers 'expand-file-name)
 269     (forward-char)
 270     (char-to-string (char-before))))
 271
 272 (defun eshell-parse-drive-letter ()
 273   "An argument beginning X:[^/] is a drive letter reference."
 274   (when (and (not eshell-current-argument)
 275              (looking-at "\\([A-Za-z]:\\)\\([^/\\\\]\\|\\'\\)"))
 276     (goto-char (match-end 1))
 277     (let* ((letter (match-string 1))
 278            (regexp (concat "\\`" letter))
 279            (path (eshell-find-previous-directory regexp)))
 280       (concat (or path letter) "/"))))
 281
 282 (defun eshell-complete-user-reference ()
 283   "If there is a user reference, complete it."
 284   (let ((arg (pcomplete-actual-arg)))
 285     (when (string-match "\\`~[a-z]*\\'" arg)
 286       (setq pcomplete-stub (substring arg 1)
 287             pcomplete-last-completion-raw t)
 288       (throw 'pcomplete-completions
 289              (progn
 290                (eshell-read-user-names)
 291                (pcomplete-uniqify-list
 292                 (mapcar
 293                  (function
 294                   (lambda (user)
 295                     (file-name-as-directory (cdr user))))
 296                  eshell-user-names)))))))
 297
 298 (defun eshell/pwd (&rest args)
 299   "Change output from `pwd` to be cleaner."
 300   (let* ((path default-directory)
 301          (len (length path)))
 302     (if (and (> len 1)
 303              (eq (aref path (1- len)) ?/)
 304              (not (and (eshell-under-windows-p)
 305                        (string-match "\\`[A-Za-z]:[\\\\/]\\'" path))))
 306         (setq path (substring path 0 (1- (length path)))))
 307     (if eshell-pwd-convert-function
 308         (funcall eshell-pwd-convert-function path)
 309       path)))
 310
 311 (defun eshell-expand-multiple-dots (path)
 312   "Convert '...' to '../..', '....' to '../../..', etc..
 313
 314 With the following piece of advice, you can make this functionality
 315 available in most of Emacs, with the exception of filename completion
 316 in the minibuffer:
 317
 318   (defadvice expand-file-name
 319     (before translate-multiple-dots
 320             (filename &optional directory) activate)
 321     (setq filename (eshell-expand-multiple-dots filename)))"
 322   (while (string-match "\\.\\.\\(\\.+\\)" path)
 323     (let* ((extra-dots (match-string 1 path))
 324            (len (length extra-dots))
 325            replace-text)
 326       (while (> len 0)
 327         (setq replace-text (concat replace-text "/..")
 328               len (1- len)))
 329       (setq path
 330             (replace-match replace-text t t path 1))))
 331   path)
 332
 333 (defun eshell-find-previous-directory (regexp)
 334   "Find the most recent last-dir matching REGEXP."
 335   (let ((index 0)
 336         (len (ring-length eshell-last-dir-ring))
 337         oldpath)
 338     (if (> (length regexp) 0)
 339         (while (< index len)
 340           (setq oldpath (ring-ref eshell-last-dir-ring index))
 341           (if (string-match regexp oldpath)
 342               (setq index len)
 343             (setq oldpath nil
 344                   index (1+ index)))))
 345     oldpath))
 346
 347 (eval-when-compile
 348   (defvar dired-directory))
 349
 350 (defun eshell/cd (&rest args)           ; all but first ignored
 351   "Alias to extend the behavior of `cd'."
 352   (setq args (eshell-flatten-list args))
 353   (let ((path (car args))
 354         (subpath (car (cdr args)))
 355         (case-fold-search (eshell-under-windows-p))
 356         handled)
 357     (if (numberp path)
 358         (setq path (number-to-string path)))
 359     (if (numberp subpath)
 360         (setq subpath (number-to-string subpath)))
 361     (cond
 362      (subpath
 363       (let ((curdir (eshell/pwd)))
 364         (if (string-match path curdir)
 365             (setq path (replace-match subpath nil nil curdir))
 366           (error "Path substring '%s' not found" path))))
 367      ((and path (string-match "^-\\([0-9]*\\)$" path))
 368       (let ((index (match-string 1 path)))
 369         (setq path
 370               (ring-remove eshell-last-dir-ring
 371                            (if index
 372                                (string-to-number index)
 373                              0)))))
 374      ((and path (string-match "^=\\(.*\\)$" path))
 375       (let ((oldpath (eshell-find-previous-directory
 376                       (match-string 1 path))))
 377         (if oldpath
 378             (setq path oldpath)
 379           (let ((len (ring-length eshell-last-dir-ring))
 380                 (index 0))
 381             (if (= len 0)
 382                 (error "Directory ring empty"))
 383             (eshell-init-print-buffer)
 384             (while (< index len)
 385               (eshell-buffered-print
 386                (concat (number-to-string index) ": "
 387                        (ring-ref eshell-last-dir-ring index) "\n"))
 388               (setq index (1+ index)))
 389             (eshell-flush)
 390             (setq handled t)))))
 391      (path
 392       (setq path (eshell-expand-multiple-dots path))))
 393     (unless handled
 394       (setq dired-directory (or path "~"))
 395       (let ((curdir (eshell/pwd)))
 396         (unless (equal curdir dired-directory)
 397           (eshell-add-to-dir-ring curdir))
 398         (let ((result (cd dired-directory)))
 399           (and eshell-cd-shows-directory
 400                (eshell-printn result)))
 401         (run-hooks 'eshell-directory-change-hook)
 402         (if eshell-list-files-after-cd
 403             (throw 'eshell-replace-command
 404                    (eshell-parse-command "ls" (cdr args))))
 405         nil))))
 406
 407 (put 'eshell/cd 'eshell-no-numeric-conversions t)
 408
 409 (defun eshell-add-to-dir-ring (path)
 410   "Add PATH to the last-dir-ring, if applicable."
 411   (unless (and (not (ring-empty-p eshell-last-dir-ring))
 412                (equal path (ring-ref eshell-last-dir-ring 0)))
 413     (if eshell-last-dir-unique
 414         (let ((index 0)
 415               (len (ring-length eshell-last-dir-ring)))
 416           (while (< index len)
 417             (if (equal (ring-ref eshell-last-dir-ring index) path)
 418                 (ring-remove eshell-last-dir-ring index)
 419               (setq index (1+ index))))))
 420     (ring-insert eshell-last-dir-ring path)))
 421
 422 ;;; pushd [+n | dir]
 423 (defun eshell/pushd (&rest args)        ; all but first ignored
 424   "Implementation of pushd in Lisp."
 425   (let ((path (car args)))
 426     (cond
 427      ((null path)
 428       ;; no arg -- swap pwd and car of stack unless eshell-pushd-tohome
 429       (cond (eshell-pushd-tohome
 430              (eshell/pushd "~"))
 431             (eshell-dirstack
 432              (let ((old (eshell/pwd)))
 433                (eshell/cd (car eshell-dirstack))
 434                (setq eshell-dirstack (cons old (cdr eshell-dirstack)))
 435                (eshell/dirs t)))
 436             (t
 437              (error "pushd: No other directory"))))
 438      ((string-match "^\\+\\([0-9]\\)" path)
 439       ;; pushd +n
 440       (setq path (string-to-number (match-string 1 path)))
 441       (cond ((> path (length eshell-dirstack))
 442              (error "Directory stack not that deep"))
 443             ((= path 0)
 444              (error "Couldn't cd"))
 445             (eshell-pushd-dextract
 446              (let ((dir (nth (1- path) eshell-dirstack)))
 447                (eshell/popd path)
 448                (eshell/pushd (eshell/pwd))
 449                (eshell/cd dir)
 450                (eshell/dirs t)))
 451             (t
 452              (let* ((ds (cons (eshell/pwd) eshell-dirstack))
 453                     (dslen (length ds))
 454                     (front (nthcdr path ds))
 455                     (back (nreverse (nthcdr (- dslen path) (reverse ds))))
 456                     (new-ds (append front back)))
 457                (eshell/cd (car new-ds))
 458                (setq eshell-dirstack (cdr new-ds))
 459                (eshell/dirs t)))))
 460      (t
 461       ;; pushd <dir>
 462       (let ((old-wd (eshell/pwd)))
 463         (eshell/cd path)
 464         (if (or (null eshell-pushd-dunique)
 465                 (not (member old-wd eshell-dirstack)))
 466             (setq eshell-dirstack (cons old-wd eshell-dirstack)))
 467         (eshell/dirs t)))))
 468   nil)
 469
 470 (put 'eshell/pushd 'eshell-no-numeric-conversions t)
 471
 472 ;;; popd [+n]
 473 (defun eshell/popd (&rest args)
 474   "Implementation of popd in Lisp."
 475   (let ((ref (or (car args) "+0")))
 476     (unless (and (stringp ref)
 477                  (string-match "\\`\\([+-][0-9]+\\)\\'" ref))
 478       (error "popd: bad arg `%s'" ref))
 479     (setq ref (string-to-number (match-string 1 ref)))
 480     (cond ((= ref 0)
 481            (unless eshell-dirstack
 482              (error "popd: Directory stack empty"))
 483            (eshell/cd (car eshell-dirstack))
 484            (setq eshell-dirstack (cdr eshell-dirstack))
 485            (eshell/dirs t))
 486           ((<= (abs ref) (length eshell-dirstack))
 487            (let* ((ds (cons nil eshell-dirstack))
 488                   (cell (nthcdr (if (> ref 0)
 489                                     (1- ref)
 490                                   (+ (length eshell-dirstack) ref)) ds))
 491                   (dir (cadr cell)))
 492              (eshell/cd dir)
 493              (setcdr cell (cdr (cdr cell)))
 494              (setq eshell-dirstack (cdr ds))
 495              (eshell/dirs t)))
 496           (t
 497            (error "Couldn't popd"))))
 498   nil)
 499
 500 (put 'eshell/popd 'eshell-no-numeric-conversions t)
 501
 502 (defun eshell/dirs (&optional if-verbose)
 503   "Implementation of dirs in Lisp."
 504   (when (or (not if-verbose) eshell-dirtrack-verbose)
 505     (let* ((msg "")
 506            (ds (cons (eshell/pwd) eshell-dirstack))
 507            (home (expand-file-name "~/"))
 508            (homelen (length home)))
 509       (while ds
 510         (let ((dir (car ds)))
 511           (and (>= (length dir) homelen)
 512                (string= home (substring dir 0 homelen))
 513                (setq dir (concat "~/" (substring dir homelen))))
 514           (setq msg (concat msg (directory-file-name dir) " "))
 515           (setq ds (cdr ds))))
 516       msg)))
 517
 518 (defun eshell-read-last-dir-ring ()
 519   "Sets the buffer's `eshell-last-dir-ring' from a history file."
 520   (let ((file eshell-last-dir-ring-file-name))
 521     (cond
 522      ((or (null file)
 523           (equal file "")
 524           (not (file-readable-p file)))
 525       nil)
 526      (t
 527       (let* ((count 0)
 528              (size eshell-last-dir-ring-size)
 529              (ring (make-ring size)))
 530         (with-temp-buffer
 531           (insert-file-contents file)
 532           ;; Save restriction in case file is already visited...
 533           ;; Watch for those date stamps in history files!
 534           (goto-char (point-max))
 535           (while (and (< count size)
 536                       (re-search-backward "^\\([^\n].*\\)$" nil t))
 537             (ring-insert-at-beginning ring (match-string 1))
 538             (setq count (1+ count)))
 539           ;; never allow the top element to equal the current
 540           ;; directory
 541           (while (and (not (ring-empty-p ring))
 542                       (equal (ring-ref ring 0) (eshell/pwd)))
 543             (ring-remove ring 0)))
 544         (setq eshell-last-dir-ring ring))))))
 545
 546 (defun eshell-write-last-dir-ring ()
 547   "Writes the buffer's `eshell-last-dir-ring' to a history file."
 548   (let ((file eshell-last-dir-ring-file-name))
 549     (cond
 550      ((or (null file)
 551           (equal file "")
 552           (null eshell-last-dir-ring)
 553           (ring-empty-p eshell-last-dir-ring))
 554       nil)
 555      ((not (file-writable-p file))
 556       (message "Cannot write last-dir-ring file %s" file))
 557      (t
 558       (let* ((ring eshell-last-dir-ring)
 559              (index (ring-length ring)))
 560         (with-temp-buffer
 561           (while (> index 0)
 562             (setq index (1- index))
 563             (insert (ring-ref ring index) ?\n))
 564           (insert (eshell/pwd) ?\n)
 565           (eshell-with-private-file-modes
 566            (write-region (point-min) (point-max) file nil
 567                          'no-message))))))))
 568
 569 ;;; Code:
 570
 571 ;;; arch-tag: 1e9c5a95-f1bd-45f8-ad36-55aac706e787
 572 ;;; em-dirs.el ends here