lisp/eshell/em-hist.el

   1 ;;; em-hist.el --- history list management
   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-hist)
  25
  26 (eval-when-compile (require 'esh-maint))
  27
  28 (defgroup eshell-hist nil
  29   "This module provides command history management."
  30   :tag "History list management"
  31   :group 'eshell-module)
  32
  33 ;;; Commentary:
  34
  35 ;; Eshell's history facility imitates the syntax used by bash
  36 ;; ([(bash)History Interaction]).  Thus:
  37 ;;
  38 ;;   !ls           ; repeat the last command beginning with 'ls'
  39 ;;   !?ls          ; repeat the last command containing ls
  40 ;;   echo !ls:2    ; echo the second arg of the last 'ls' command
  41 ;;   !ls<tab>      ; complete against all possible words in this
  42 ;;                 ; position, by looking at the history list
  43 ;;   !ls<C-c SPC>  ; expand any matching history input at point
  44 ;;
  45 ;; Also, most of `comint-mode's keybindings are accepted:
  46 ;;
  47 ;;   M-r     ; search backward for a previous command by regexp
  48 ;;   M-s     ; search forward for a previous command by regexp
  49 ;;   M-p     ; access the last command entered, repeatable
  50 ;;   M-n     ; access the first command entered, repeatable
  51 ;;
  52 ;;   C-c M-r ; using current input, find a matching command thus, with
  53 ;;           ; 'ls' as the current input, it will go back to the same
  54 ;;           ; command that '!ls' would have selected
  55 ;;   C-c M-s ; same, but in reverse order
  56 ;;
  57 ;; Note that some of these keybindings are only available if the
  58 ;; `eshell-rebind' is not in use, in which case M-p does what C-c M-r
  59 ;; normally would do, and C-p is used instead of M-p.  It may seem
  60 ;; confusing, but the intention is to make the most useful
  61 ;; functionality the most easily accessible.  If `eshell-rebind' is
  62 ;; not being used, history navigation will use comint's keybindings;
  63 ;; if it is, history navigation tries to use similar keybindings to
  64 ;; bash.  This is all configurable, of course.
  65
  66 ;;; Code:
  67
  68 (require 'ring)
  69 (require 'esh-opt)
  70 (require 'em-pred)
  71
  72 ;;; User Variables:
  73
  74 (defcustom eshell-hist-load-hook '(eshell-hist-initialize)
  75   "*A list of functions to call when loading `eshell-hist'."
  76   :type 'hook
  77   :group 'eshell-hist)
  78
  79 (defcustom eshell-hist-unload-hook
  80   (list
  81    (function
  82     (lambda ()
  83       (remove-hook 'kill-emacs-hook 'eshell-save-some-history))))
  84   "*A hook that gets run when `eshell-hist' is unloaded."
  85   :type 'hook
  86   :group 'eshell-hist)
  87
  88 (defcustom eshell-history-file-name
  89   (concat eshell-directory-name "history")
  90   "*If non-nil, name of the file to read/write input history.
  91 See also `eshell-read-history' and `eshell-write-history'.
  92 If it is nil, Eshell will use the value of HISTFILE."
  93   :type 'file
  94   :group 'eshell-hist)
  95
  96 (defcustom eshell-history-size 128
  97   "*Size of the input history ring.  If nil, use envvar HISTSIZE."
  98   :type 'integer
  99   :group 'eshell-hist)
 100
 101 (defcustom eshell-hist-ignoredups nil
 102   "*If non-nil, don't add input matching the last on the input ring.
 103 This mirrors the optional behavior of bash."
 104   :type 'boolean
 105   :group 'eshell-hist)
 106
 107 (defcustom eshell-save-history-on-exit 'ask
 108   "*Determine if history should be automatically saved.
 109 History is always preserved after sanely exiting an Eshell buffer.
 110 However, when Emacs is being shut down, this variable determines
 111 whether to prompt the user.
 112 If set to nil, it means never save history on termination of Emacs.
 113 If set to `ask', ask if any Eshell buffers are open at exit time.
 114 If set to t, history will always be saved, silently."
 115   :type '(choice (const :tag "Never" nil)
 116                  (const :tag "Ask" ask)
 117                  (const :tag "Always save" t))
 118   :group 'eshell-hist)
 119
 120 (defcustom eshell-input-filter
 121   (function
 122    (lambda (str)
 123      (not (string-match "\\`\\s-*\\'" str))))
 124   "*Predicate for filtering additions to input history.
 125 Takes one argument, the input.  If non-nil, the input may be saved on
 126 the input history list.  Default is to save anything that isn't all
 127 whitespace."
 128   :type 'function
 129   :group 'eshell-hist)
 130
 131 (put 'eshell-input-filter 'risky-local-variable t)
 132
 133 (defcustom eshell-hist-match-partial t
 134   "*If non-nil, movement through history is constrained by current input.
 135 Otherwise, typing <M-p> and <M-n> will always go to the next history
 136 element, regardless of any text on the command line.  In that case,
 137 <C-c M-r> and <C-c M-s> still offer that functionality."
 138   :type 'boolean
 139   :group 'eshell-hist)
 140
 141 (defcustom eshell-hist-move-to-end t
 142   "*If non-nil, move to the end of the buffer before cycling history."
 143   :type 'boolean
 144   :group 'eshell-hist)
 145
 146 (defcustom eshell-hist-event-designator
 147   "^!\\(!\\|-?[0-9]+\\|\\??[^:^$%*?]+\\??\\|#\\)"
 148   "*The regexp used to identifier history event designators."
 149   :type 'regexp
 150   :group 'eshell-hist)
 151
 152 (defcustom eshell-hist-word-designator
 153   "^:?\\([0-9]+\\|[$^%*]\\)?\\(\\*\\|-[0-9]*\\|[$^%*]\\)?"
 154   "*The regexp used to identify history word designators."
 155   :type 'regexp
 156   :group 'eshell-hist)
 157
 158 (defcustom eshell-hist-modifier
 159   "^\\(:\\([hretpqx&g]\\|s/\\([^/]*\\)/\\([^/]*\\)/\\)\\)*"
 160   "*The regexp used to identity history modifiers."
 161   :type 'regexp
 162   :group 'eshell-hist)
 163
 164 (defcustom eshell-hist-rebind-keys-alist
 165   '(([(control ?p)]   . eshell-previous-input)
 166     ([(control ?n)]   . eshell-next-input)
 167     ([(control up)]   . eshell-previous-input)
 168     ([(control down)] . eshell-next-input)
 169     ([(control ?r)]   . eshell-isearch-backward)
 170     ([(control ?s)]   . eshell-isearch-forward)
 171     ([(meta ?r)]      . eshell-previous-matching-input)
 172     ([(meta ?s)]      . eshell-next-matching-input)
 173     ([(meta ?p)]      . eshell-previous-matching-input-from-input)
 174     ([(meta ?n)]      . eshell-next-matching-input-from-input)
 175     ([up]             . eshell-previous-matching-input-from-input)
 176     ([down]           . eshell-next-matching-input-from-input))
 177   "*History keys to bind differently if point is in input text."
 178   :type '(repeat (cons (vector :tag "Keys to bind"
 179                                (repeat :inline t sexp))
 180                        (function :tag "Command")))
 181   :group 'eshell-hist)
 182
 183 ;;; Internal Variables:
 184
 185 (defvar eshell-history-ring nil)
 186 (defvar eshell-history-index nil)
 187 (defvar eshell-matching-input-from-input-string "")
 188 (defvar eshell-save-history-index nil)
 189
 190 (defvar eshell-isearch-map nil)
 191
 192 (unless eshell-isearch-map
 193   (setq eshell-isearch-map (copy-keymap isearch-mode-map))
 194   (define-key eshell-isearch-map [(control ?m)] 'eshell-isearch-return)
 195   (define-key eshell-isearch-map [return] 'eshell-isearch-return)
 196   (define-key eshell-isearch-map [(control ?r)] 'eshell-isearch-repeat-backward)
 197   (define-key eshell-isearch-map [(control ?s)] 'eshell-isearch-repeat-forward)
 198   (define-key eshell-isearch-map [(control ?g)] 'eshell-isearch-abort)
 199   (define-key eshell-isearch-map [backspace] 'eshell-isearch-delete-char)
 200   (define-key eshell-isearch-map [delete] 'eshell-isearch-delete-char)
 201   (defvar eshell-isearch-cancel-map)
 202   (define-prefix-command 'eshell-isearch-cancel-map)
 203   (define-key eshell-isearch-map [(control ?c)] 'eshell-isearch-cancel-map)
 204   (define-key eshell-isearch-cancel-map [(control ?c)] 'eshell-isearch-cancel))
 205
 206 ;;; Functions:
 207
 208 (defun eshell-hist-initialize ()
 209   "Initialize the history management code for one Eshell buffer."
 210   (add-hook 'eshell-expand-input-functions
 211             'eshell-expand-history-references nil t)
 212
 213   (when (eshell-using-module 'eshell-cmpl)
 214     (add-hook 'pcomplete-try-first-hook
 215               'eshell-complete-history-reference nil t))
 216
 217   (if (and (eshell-using-module 'eshell-rebind)
 218            (not eshell-non-interactive-p))
 219       (let ((rebind-alist (symbol-value 'eshell-rebind-keys-alist)))
 220         (make-local-variable 'eshell-rebind-keys-alist)
 221         (set 'eshell-rebind-keys-alist
 222              (append rebind-alist eshell-hist-rebind-keys-alist))
 223         (set (make-local-variable 'search-invisible) t)
 224         (set (make-local-variable 'search-exit-option) t)
 225         (add-hook 'isearch-mode-hook
 226                   (function
 227                    (lambda ()
 228                      (if (>= (point) eshell-last-output-end)
 229                          (setq overriding-terminal-local-map
 230                                eshell-isearch-map)))) nil t)
 231         (add-hook 'isearch-mode-end-hook
 232                   (function
 233                    (lambda ()
 234                      (setq overriding-terminal-local-map nil))) nil t))
 235     (define-key eshell-mode-map [up] 'eshell-previous-matching-input-from-input)
 236     (define-key eshell-mode-map [down] 'eshell-next-matching-input-from-input)
 237     (define-key eshell-mode-map [(control up)] 'eshell-previous-input)
 238     (define-key eshell-mode-map [(control down)] 'eshell-next-input)
 239     (define-key eshell-mode-map [(meta ?r)] 'eshell-previous-matching-input)
 240     (define-key eshell-mode-map [(meta ?s)] 'eshell-next-matching-input)
 241     (define-key eshell-command-map [(meta ?r)]
 242       'eshell-previous-matching-input-from-input)
 243     (define-key eshell-command-map [(meta ?s)]
 244       'eshell-next-matching-input-from-input)
 245     (if eshell-hist-match-partial
 246         (progn
 247           (define-key eshell-mode-map [(meta ?p)]
 248             'eshell-previous-matching-input-from-input)
 249           (define-key eshell-mode-map [(meta ?n)]
 250             'eshell-next-matching-input-from-input)
 251           (define-key eshell-command-map [(meta ?p)] 'eshell-previous-input)
 252           (define-key eshell-command-map [(meta ?n)] 'eshell-next-input))
 253       (define-key eshell-mode-map [(meta ?p)] 'eshell-previous-input)
 254       (define-key eshell-mode-map [(meta ?n)] 'eshell-next-input)
 255       (define-key eshell-command-map [(meta ?p)]
 256         'eshell-previous-matching-input-from-input)
 257       (define-key eshell-command-map [(meta ?n)]
 258         'eshell-next-matching-input-from-input)))
 259
 260   (make-local-variable 'eshell-history-size)
 261   (or eshell-history-size
 262       (setq eshell-history-size (getenv "HISTSIZE")))
 263
 264   (make-local-variable 'eshell-history-file-name)
 265   (or eshell-history-file-name
 266       (setq eshell-history-file-name (getenv "HISTFILE")))
 267
 268   (make-local-variable 'eshell-history-index)
 269   (make-local-variable 'eshell-save-history-index)
 270
 271   (if (minibuffer-window-active-p (selected-window))
 272       (set (make-local-variable 'eshell-save-history-on-exit) nil)
 273     (set (make-local-variable 'eshell-history-ring) nil)
 274     (if eshell-history-file-name
 275         (eshell-read-history nil t))
 276
 277     (add-hook 'eshell-exit-hook 'eshell-write-history nil t))
 278
 279   (unless eshell-history-ring
 280     (setq eshell-history-ring (make-ring eshell-history-size)))
 281
 282   (add-hook 'eshell-exit-hook 'eshell-write-history nil t)
 283
 284   (add-hook 'kill-emacs-hook 'eshell-save-some-history)
 285
 286   (make-local-variable 'eshell-input-filter-functions)
 287   (add-hook 'eshell-input-filter-functions 'eshell-add-to-history nil t)
 288
 289   (define-key eshell-command-map [(control ?l)] 'eshell-list-history)
 290   (define-key eshell-command-map [(control ?x)] 'eshell-get-next-from-history))
 291
 292 (defun eshell-save-some-history ()
 293   "Save the history for any open Eshell buffers."
 294   (eshell-for buf (buffer-list)
 295     (if (buffer-live-p buf)
 296         (with-current-buffer buf
 297           (if (and eshell-mode
 298                    eshell-history-file-name
 299                    eshell-save-history-on-exit
 300                    (or (eq eshell-save-history-on-exit t)
 301                        (y-or-n-p
 302                         (format "Save input history for Eshell buffer `%s'? "
 303                                 (buffer-name buf)))))
 304               (eshell-write-history))))))
 305
 306 (defun eshell/history (&rest args)
 307   "List in help buffer the buffer's input history."
 308   (eshell-init-print-buffer)
 309   (eshell-eval-using-options
 310    "history" args
 311    '((?r "read" nil read-history
 312          "read from history file to current history list")
 313      (?w "write" nil write-history
 314          "write current history list to history file")
 315      (?a "append" nil append-history
 316          "append current history list to history file")
 317      (?h "help" nil nil "display this usage message")
 318      :usage "[n] [-rwa [filename]]"
 319      :post-usage
 320 "When Eshell is started, history is read from `eshell-history-file-name'.
 321 This is also the location where history info will be saved by this command,
 322 unless a different file is specified on the command line.")
 323    (and (or (not (ring-p eshell-history-ring))
 324            (ring-empty-p eshell-history-ring))
 325         (error "No history"))
 326    (let (length command file)
 327      (when (and args (string-match "^[0-9]+$" (car args)))
 328        (setq length (min (eshell-convert (car args))
 329                          (ring-length eshell-history-ring))
 330              args (cdr args)))
 331      (and length
 332           (or read-history write-history append-history)
 333           (error "history: extra arguments"))
 334      (when (and args (stringp (car args)))
 335        (setq file (car args)
 336              args (cdr args)))
 337      (cond
 338       (read-history (eshell-read-history file))
 339       (write-history (eshell-write-history file))
 340       (append-history (eshell-write-history file t))
 341       (t
 342        (let* ((history nil)
 343               (index (1- (or length (ring-length eshell-history-ring))))
 344               (ref (- (ring-length eshell-history-ring) index)))
 345          ;; We have to build up a list ourselves from the ring vector.
 346          (while (>= index 0)
 347            (eshell-buffered-print
 348             (format "%5d  %s\n" ref (eshell-get-history index)))
 349            (setq index (1- index)
 350                  ref (1+ ref)))))))
 351    (eshell-flush)
 352    nil))
 353
 354 (defun eshell-put-history (input &optional ring at-beginning)
 355   "Put a new input line into the history ring."
 356   (unless ring (setq ring eshell-history-ring))
 357   (if at-beginning
 358       (ring-insert-at-beginning ring input)
 359     (ring-insert ring input)))
 360
 361 (defun eshell-get-history (index &optional ring)
 362   "Get an input line from the history ring."
 363   (ring-ref (or ring eshell-history-ring) index))
 364
 365 (defun eshell-add-input-to-history (input)
 366   "Add the string INPUT to the history ring.
 367 Input is entered into the input history ring, if the value of
 368 variable `eshell-input-filter' returns non-nil when called on the
 369 input."
 370   (if (and (funcall eshell-input-filter input)
 371            (or (null eshell-hist-ignoredups)
 372                (not (ring-p eshell-history-ring))
 373                (ring-empty-p eshell-history-ring)
 374                (not (string-equal (eshell-get-history 0) input))))
 375       (eshell-put-history input))
 376   (setq eshell-save-history-index eshell-history-index)
 377   (setq eshell-history-index nil))
 378
 379 (defun eshell-add-command-to-history ()
 380   "Add the command entered at `eshell-command's prompt to the history ring.
 381 The command is added to the input history ring, if the value of
 382 variable `eshell-input-filter' returns non-nil when called on the
 383 command.
 384
 385 This function is supposed to be called from the minibuffer, presumably
 386 as a minibuffer-exit-hook."
 387   (eshell-add-input-to-history
 388    (buffer-substring (minibuffer-prompt-end) (point-max))))
 389
 390 (defun eshell-add-to-history ()
 391   "Add last Eshell command to the history ring.
 392 The command is entered into the input history ring, if the value of
 393 variable `eshell-input-filter' returns non-nil when called on the
 394 command."
 395   (when (> (1- eshell-last-input-end) eshell-last-input-start)
 396     (let ((input (buffer-substring eshell-last-input-start
 397                                    (1- eshell-last-input-end))))
 398       (eshell-add-input-to-history input))))
 399
 400 (defun eshell-read-history (&optional filename silent)
 401   "Sets the buffer's `eshell-history-ring' from a history file.
 402 The name of the file is given by the variable
 403 `eshell-history-file-name'.  The history ring is of size
 404 `eshell-history-size', regardless of file size.  If
 405 `eshell-history-file-name' is nil this function does nothing.
 406
 407 If the optional argument SILENT is non-nil, we say nothing about a
 408 failure to read the history file.
 409
 410 This function is useful for major mode commands and mode hooks.
 411
 412 The structure of the history file should be one input command per
 413 line, with the most recent command last.  See also
 414 `eshell-hist-ignoredups' and `eshell-write-history'."
 415   (let ((file (or filename eshell-history-file-name)))
 416     (cond
 417      ((or (null file)
 418           (equal file ""))
 419       nil)
 420      ((not (file-readable-p file))
 421       (or silent
 422           (message "Cannot read history file %s" file)))
 423      (t
 424       (let* ((count 0)
 425              (size eshell-history-size)
 426              (ring (make-ring size))
 427              (ignore-dups eshell-hist-ignoredups))
 428         (with-temp-buffer
 429           (insert-file-contents file)
 430           ;; Save restriction in case file is already visited...
 431           ;; Watch for those date stamps in history files!
 432           (goto-char (point-max))
 433           (while (and (< count size)
 434                       (re-search-backward "^[ \t]*\\([^#\n].*\\)[ \t]*$"
 435                                           nil t))
 436             (let ((history (match-string 1)))
 437               (if (or (null ignore-dups)
 438                       (ring-empty-p ring)
 439                       (not (string-equal (ring-ref ring 0) history)))
 440                   (ring-insert-at-beginning
 441                    ring (subst-char-in-string ?\177 ?\n history))))
 442             (setq count (1+ count))))
 443         (setq eshell-history-ring ring
 444               eshell-history-index nil))))))
 445
 446 (defun eshell-write-history (&optional filename append)
 447   "Writes the buffer's `eshell-history-ring' to a history file.
 448 The name of the file is given by the variable
 449 `eshell-history-file-name'.  The original contents of the file are
 450 lost if `eshell-history-ring' is not empty.  If
 451 `eshell-history-file-name' is nil this function does nothing.
 452
 453 Useful within process sentinels.
 454
 455 See also `eshell-read-history'."
 456   (let ((file (or filename eshell-history-file-name)))
 457     (cond
 458      ((or (null file)
 459           (equal file "")
 460           (null eshell-history-ring)
 461           (ring-empty-p eshell-history-ring))
 462       nil)
 463      ((not (file-writable-p file))
 464       (message "Cannot write history file %s" file))
 465      (t
 466       (let* ((ring eshell-history-ring)
 467              (index (ring-length ring)))
 468         ;; Write it all out into a buffer first.  Much faster, but
 469         ;; messier, than writing it one line at a time.
 470         (with-temp-buffer
 471           (while (> index 0)
 472             (setq index (1- index))
 473             (let ((start (point)))
 474               (insert (ring-ref ring index) ?\n)
 475               (subst-char-in-region start (1- (point)) ?\n ?\177)))
 476           (eshell-with-private-file-modes
 477            (write-region (point-min) (point-max) file append
 478                          'no-message))))))))
 479
 480 (defun eshell-list-history ()
 481   "List in help buffer the buffer's input history."
 482   (interactive)
 483   (let (prefix prelen)
 484     (save-excursion
 485       (if (re-search-backward "!\\(.+\\)" (line-beginning-position) t)
 486           (setq prefix (match-string 1)
 487                 prelen (length prefix))))
 488     (if (or (not (ring-p eshell-history-ring))
 489             (ring-empty-p eshell-history-ring))
 490         (message "No history")
 491       (let ((history nil)
 492             (history-buffer " *Input History*")
 493             (index (1- (ring-length eshell-history-ring)))
 494             (conf (current-window-configuration)))
 495         ;; We have to build up a list ourselves from the ring vector.
 496         (while (>= index 0)
 497           (let ((hist (eshell-get-history index)))
 498             (if (or (not prefix)
 499                     (and (>= (length hist) prelen)
 500                          (string= (substring hist 0 prelen) prefix)))
 501                 (setq history (cons hist history))))
 502           (setq index (1- index)))
 503         ;; Change "completion" to "history reference"
 504         ;; to make the display accurate.
 505         (with-output-to-temp-buffer history-buffer
 506           (display-completion-list history)
 507           (set-buffer history-buffer)
 508           (forward-line 3)
 509           (while (search-backward "completion" nil 'move)
 510             (replace-match "history reference")))
 511         (eshell-redisplay)
 512         (message "Hit space to flush")
 513         (let ((ch (read-event)))
 514           (if (eq ch ?\ )
 515               (set-window-configuration conf)
 516             (setq unread-command-events (list ch))))))))
 517
 518 (defun eshell-hist-word-reference (ref)
 519   "Return the word designator index referred to by REF."
 520   (cond
 521    ((string-match "^[0-9]+$" ref)
 522     (string-to-number ref))
 523    ((string= "^" ref) 1)
 524    ((string= "$" ref) nil)
 525    ((string= "%" ref)
 526     (error "`%' history word designator not yet implemented"))))
 527
 528 (defun eshell-hist-parse-arguments (&optional silent b e)
 529   "Parse current command arguments in a history-code-friendly way."
 530   (let ((end (or e (point)))
 531         (begin (or b (save-excursion (eshell-bol) (point))))
 532         (posb (list t))
 533         (pose (list t))
 534         (textargs (list t))
 535         hist args)
 536     (unless (catch 'eshell-incomplete
 537               (ignore
 538                (setq args (eshell-parse-arguments begin end))))
 539       (save-excursion
 540         (goto-char begin)
 541         (while (< (point) end)
 542           (if (get-text-property (point) 'arg-begin)
 543               (nconc posb (list (point))))
 544           (if (get-text-property (point) 'arg-end)
 545               (nconc pose
 546                      (list (if (= (1+ (point)) end)
 547                                (1+ (point))
 548                              (point)))))
 549           (forward-char))
 550         (setq posb (cdr posb)
 551               pose (cdr pose))
 552         (assert (= (length posb) (length args)))
 553         (assert (<= (length posb) (length pose))))
 554       (setq hist (buffer-substring-no-properties begin end))
 555       (let ((b posb) (e pose))
 556         (while b
 557           (nconc textargs
 558                  (list (substring hist (- (car b) begin)
 559                                   (- (car e) begin))))
 560           (setq b (cdr b)
 561                 e (cdr e))))
 562       (setq textargs (cdr textargs))
 563       (assert (= (length textargs) (length args)))
 564       (list textargs posb pose))))
 565
 566 (defun eshell-expand-history-references (beg end)
 567   "Parse and expand any history references in current input."
 568   (let ((result (eshell-hist-parse-arguments t beg end)))
 569     (when result
 570       (let ((textargs (nreverse (nth 0 result)))
 571             (posb (nreverse (nth 1 result)))
 572             (pose (nreverse (nth 2 result))))
 573         (save-excursion
 574           (while textargs
 575             (let ((str (eshell-history-reference (car textargs))))
 576               (unless (eq str (car textargs))
 577                 (goto-char (car posb))
 578                 (insert-and-inherit str)
 579                 (delete-char (- (car pose) (car posb)))))
 580             (setq textargs (cdr textargs)
 581                   posb (cdr posb)
 582                   pose (cdr pose))))))))
 583
 584 (defun eshell-complete-history-reference ()
 585   "Complete a history reference, by completing the event designator."
 586   (let ((arg (pcomplete-actual-arg)))
 587     (when (string-match "\\`![^:^$*%]*\\'" arg)
 588       (setq pcomplete-stub (substring arg 1)
 589             pcomplete-last-completion-raw t)
 590       (throw 'pcomplete-completions
 591              (let ((history nil)
 592                    (index (1- (ring-length eshell-history-ring)))
 593                    (stublen (length pcomplete-stub)))
 594                ;; We have to build up a list ourselves from the ring
 595                ;; vector.
 596                (while (>= index 0)
 597                  (let ((hist (eshell-get-history index)))
 598                    (if (and (>= (length hist) stublen)
 599                             (string= (substring hist 0 stublen)
 600                                      pcomplete-stub)
 601                             (string-match "^\\([^:^$*% \t\n]+\\)" hist))
 602                        (setq history (cons (match-string 1 hist)
 603                                            history))))
 604                  (setq index (1- index)))
 605                (let ((fhist (list t)))
 606                  ;; uniqify the list, but preserve the order
 607                  (while history
 608                    (unless (member (car history) fhist)
 609                      (nconc fhist (list (car history))))
 610                    (setq history (cdr history)))
 611                  (cdr fhist)))))))
 612
 613 (defun eshell-history-reference (reference)
 614   "Expand directory stack REFERENCE.
 615 The syntax used here was taken from the Bash info manual.
 616 Returns the resultant reference, or the same string REFERENCE if none
 617 matched."
 618   ;; `^string1^string2^'
 619   ;;      Quick Substitution.  Repeat the last command, replacing
 620   ;;      STRING1 with STRING2.  Equivalent to `!!:s/string1/string2/'
 621   (if (and (eshell-using-module 'eshell-pred)
 622            (string-match "\\^\\([^^]+\\)\\^\\([^^]+\\)\\^?\\s-*$"
 623                          reference))
 624       (setq reference (format "!!:s/%s/%s/"
 625                               (match-string 1 reference)
 626                               (match-string 2 reference))))
 627   ;; `!'
 628   ;;      Start a history substitution, except when followed by a
 629   ;;      space, tab, the end of the line, = or (.
 630   (if (not (string-match "^![^ \t\n=\(]" reference))
 631       reference
 632     (setq eshell-history-index nil)
 633     (let ((event (eshell-hist-parse-event-designator reference)))
 634       (unless event
 635         (error "Could not find history event `%s'" reference))
 636       (setq eshell-history-index (car event)
 637             reference (substring reference (cdr event))
 638             event (eshell-get-history eshell-history-index))
 639       (if (not (string-match "^[:^$*%]" reference))
 640           event
 641         (let ((word (eshell-hist-parse-word-designator
 642                      event reference)))
 643           (unless word
 644             (error "Unable to honor word designator `%s'" reference))
 645           (unless (string-match "^[:^$*%][[$^*%0-9-]" reference)
 646             (setcdr word 0))
 647           (setq event (car word)
 648                 reference (substring reference (cdr word)))
 649           (if (not (and (eshell-using-module 'eshell-pred)
 650                         (string-match "^:" reference)))
 651               event
 652             (eshell-hist-parse-modifier event reference)))))))
 653
 654 (defun eshell-hist-parse-event-designator (reference)
 655   "Parse a history event designator beginning in REFERENCE."
 656   (let* ((index (string-match eshell-hist-event-designator reference))
 657          (end (and index (match-end 0))))
 658     (unless index
 659       (error "Invalid history event designator `%s'" reference))
 660     (let* ((event (match-string 1 reference))
 661            (pos
 662             (cond
 663              ((string= event "!") (ring-length eshell-history-ring))
 664              ((string= event "#") (error "!# not yet implemented"))
 665              ((string-match "^-?[0-9]+$" event)
 666               (let ((num (string-to-number event)))
 667                 (if (>= num 0)
 668                     (- (ring-length eshell-history-ring) num)
 669                   (1- (abs num)))))
 670              ((string-match "^\\(\\??\\)\\([^?]+\\)\\??$" event)
 671               (let ((pref (if (> (length (match-string 1 event)) 0)
 672                               "" "^"))
 673                     (str (match-string 2 event)))
 674                 (save-match-data
 675                   (eshell-previous-matching-input-string-position
 676                    (concat pref (regexp-quote str)) 1))))
 677              (t
 678               (error "Failed to parse event designator `%s'" event)))))
 679       (and pos (cons pos end)))))
 680
 681 (defun eshell-hist-parse-word-designator (hist reference)
 682   "Parse a history word designator beginning for HIST in REFERENCE."
 683   (let* ((index (string-match eshell-hist-word-designator reference))
 684          (end (and index (match-end 0))))
 685     (unless (memq (aref reference 0) '(?: ?^ ?$ ?* ?%))
 686       (error "Invalid history word designator `%s'" reference))
 687     (let ((nth (match-string 1 reference))
 688           (mth (match-string 2 reference))
 689           (here (point))
 690           textargs)
 691       (insert hist)
 692       (setq textargs (car (eshell-hist-parse-arguments nil here (point))))
 693       (delete-region here (point))
 694       (if (string= nth "*")
 695           (if mth
 696               (error "Invalid history word designator `%s'"
 697                      reference)
 698             (setq nth 1 mth "-$")))
 699       (if (not mth)
 700           (if nth
 701               (setq mth nth)
 702             (setq nth 0 mth "$"))
 703         (if (string= mth "-")
 704             (setq mth (- (length textargs) 2))
 705           (if (string= mth "*")
 706               (setq mth "$")
 707             (if (not (and (> (length mth) 1)
 708                           (eq (aref mth 0) ?-)))
 709                 (error "Invalid history word designator `%s'"
 710                        reference)
 711               (setq mth (substring mth 1))))))
 712       (unless (numberp nth)
 713         (setq nth (eshell-hist-word-reference nth)))
 714       (unless (numberp mth)
 715         (setq mth (eshell-hist-word-reference mth)))
 716       (cons (mapconcat 'identity (eshell-sublist textargs nth mth) "")
 717             end))))
 718
 719 (defun eshell-hist-parse-modifier (hist reference)
 720   "Parse a history modifier beginning for HIST in REFERENCE."
 721   (let ((here (point)))
 722     (insert reference)
 723     (prog1
 724         (save-restriction
 725           (narrow-to-region here (point))
 726           (goto-char (point-min))
 727           (let ((modifiers (cdr (eshell-parse-modifiers))))
 728             (eshell-for mod modifiers
 729               (setq hist (funcall mod hist)))
 730             hist))
 731       (delete-region here (point)))))
 732
 733 (defun eshell-get-next-from-history ()
 734   "After fetching a line from input history, this fetches the next.
 735 In other words, this recalls the input line after the line you
 736 recalled last.  You can use this to repeat a sequence of input lines."
 737   (interactive)
 738   (if eshell-save-history-index
 739       (progn
 740         (setq eshell-history-index (1+ eshell-save-history-index))
 741         (eshell-next-input 1))
 742     (message "No previous history command")))
 743
 744 (defun eshell-search-arg (arg)
 745   ;; First make sure there is a ring and that we are after the process
 746   ;; mark
 747   (if (and eshell-hist-move-to-end
 748            (< (point) eshell-last-output-end))
 749       (goto-char eshell-last-output-end))
 750   (cond ((or (null eshell-history-ring)
 751              (ring-empty-p eshell-history-ring))
 752          (error "Empty input ring"))
 753         ((zerop arg)
 754          ;; arg of zero resets search from beginning, and uses arg of
 755          ;; 1
 756          (setq eshell-history-index nil)
 757          1)
 758         (t
 759          arg)))
 760
 761 (defun eshell-search-start (arg)
 762   "Index to start a directional search, starting at `eshell-history-index'."
 763   (if eshell-history-index
 764       ;; If a search is running, offset by 1 in direction of arg
 765       (mod (+ eshell-history-index (if (> arg 0) 1 -1))
 766            (ring-length eshell-history-ring))
 767     ;; For a new search, start from beginning or end, as appropriate
 768     (if (>= arg 0)
 769         0                               ; First elt for forward search
 770       ;; Last elt for backward search
 771       (1- (ring-length eshell-history-ring)))))
 772
 773 (defun eshell-previous-input-string (arg)
 774   "Return the string ARG places along the input ring.
 775 Moves relative to `eshell-history-index'."
 776   (eshell-get-history (if eshell-history-index
 777                           (mod (+ arg eshell-history-index)
 778                                (ring-length eshell-history-ring))
 779                         arg)))
 780
 781 (defun eshell-previous-input (arg)
 782   "Cycle backwards through input history."
 783   (interactive "*p")
 784   (eshell-previous-matching-input "." arg))
 785
 786 (defun eshell-next-input (arg)
 787   "Cycle forwards through input history."
 788   (interactive "*p")
 789   (eshell-previous-input (- arg)))
 790
 791 (defun eshell-previous-matching-input-string (regexp arg)
 792   "Return the string matching REGEXP ARG places along the input ring.
 793 Moves relative to `eshell-history-index'."
 794   (let* ((pos (eshell-previous-matching-input-string-position regexp arg)))
 795     (if pos (eshell-get-history pos))))
 796
 797 (defun eshell-previous-matching-input-string-position
 798   (regexp arg &optional start)
 799   "Return the index matching REGEXP ARG places along the input ring.
 800 Moves relative to START, or `eshell-history-index'."
 801   (if (or (not (ring-p eshell-history-ring))
 802           (ring-empty-p eshell-history-ring))
 803       (error "No history"))
 804   (let* ((len (ring-length eshell-history-ring))
 805          (motion (if (> arg 0) 1 -1))
 806          (n (mod (- (or start (eshell-search-start arg)) motion) len))
 807          (tried-each-ring-item nil)
 808          (case-fold-search (eshell-under-windows-p))
 809          (prev nil))
 810     ;; Do the whole search as many times as the argument says.
 811     (while (and (/= arg 0) (not tried-each-ring-item))
 812       ;; Step once.
 813       (setq prev n
 814             n (mod (+ n motion) len))
 815       ;; If we haven't reached a match, step some more.
 816       (while (and (< n len) (not tried-each-ring-item)
 817                   (not (string-match regexp (eshell-get-history n))))
 818         (setq n (mod (+ n motion) len)
 819               ;; If we have gone all the way around in this search.
 820               tried-each-ring-item (= n prev)))
 821       (setq arg (if (> arg 0) (1- arg) (1+ arg))))
 822     ;; Now that we know which ring element to use, if we found it,
 823     ;; return that.
 824     (if (string-match regexp (eshell-get-history n))
 825         n)))
 826
 827 (defun eshell-previous-matching-input (regexp arg)
 828   "Search backwards through input history for match for REGEXP.
 829 \(Previous history elements are earlier commands.)
 830 With prefix argument N, search for Nth previous match.
 831 If N is negative, find the next or Nth next match."
 832   (interactive (eshell-regexp-arg "Previous input matching (regexp): "))
 833   (setq arg (eshell-search-arg arg))
 834   (let ((pos (eshell-previous-matching-input-string-position regexp arg)))
 835     ;; Has a match been found?
 836     (if (null pos)
 837         (error "Not found")
 838       (setq eshell-history-index pos)
 839       (unless (minibuffer-window-active-p (selected-window))
 840         (message "History item: %d" (- (ring-length eshell-history-ring) pos)))
 841        ;; Can't use kill-region as it sets this-command
 842       (delete-region (save-excursion (eshell-bol) (point)) (point))
 843       (insert-and-inherit (eshell-get-history pos)))))
 844
 845 (defun eshell-next-matching-input (regexp arg)
 846   "Search forwards through input history for match for REGEXP.
 847 \(Later history elements are more recent commands.)
 848 With prefix argument N, search for Nth following match.
 849 If N is negative, find the previous or Nth previous match."
 850   (interactive (eshell-regexp-arg "Next input matching (regexp): "))
 851   (eshell-previous-matching-input regexp (- arg)))
 852
 853 (defun eshell-previous-matching-input-from-input (arg)
 854   "Search backwards through input history for match for current input.
 855 \(Previous history elements are earlier commands.)
 856 With prefix argument N, search for Nth previous match.
 857 If N is negative, search forwards for the -Nth following match."
 858   (interactive "p")
 859   (if (not (memq last-command '(eshell-previous-matching-input-from-input
 860                                 eshell-next-matching-input-from-input)))
 861       ;; Starting a new search
 862       (setq eshell-matching-input-from-input-string
 863             (buffer-substring (save-excursion (eshell-bol) (point))
 864                               (point))
 865             eshell-history-index nil))
 866   (eshell-previous-matching-input
 867    (concat "^" (regexp-quote eshell-matching-input-from-input-string))
 868    arg))
 869
 870 (defun eshell-next-matching-input-from-input (arg)
 871   "Search forwards through input history for match for current input.
 872 \(Following history elements are more recent commands.)
 873 With prefix argument N, search for Nth following match.
 874 If N is negative, search backwards for the -Nth previous match."
 875   (interactive "p")
 876   (eshell-previous-matching-input-from-input (- arg)))
 877
 878 (defun eshell-test-imatch ()
 879   "If isearch match good, put point at the beginning and return non-nil."
 880   (if (get-text-property (point) 'history)
 881       (progn (beginning-of-line) t)
 882     (let ((before (point)))
 883       (eshell-bol)
 884       (if (and (not (bolp))
 885                (<= (point) before))
 886           t
 887         (if isearch-forward
 888             (progn
 889               (end-of-line)
 890               (forward-char))
 891           (beginning-of-line)
 892           (backward-char))))))
 893
 894 (defun eshell-return-to-prompt ()
 895   "Once a search string matches, insert it at the end and go there."
 896   (setq isearch-other-end nil)
 897   (let ((found (eshell-test-imatch)) before)
 898     (while (and (not found)
 899                 (setq before
 900                       (funcall (if isearch-forward
 901                                    're-search-forward
 902                                  're-search-backward)
 903                                isearch-string nil t)))
 904       (setq found (eshell-test-imatch)))
 905     (if (not found)
 906         (progn
 907           (goto-char eshell-last-output-end)
 908           (delete-region (point) (point-max)))
 909       (setq before (point))
 910       (let ((text (buffer-substring-no-properties
 911                    (point) (line-end-position)))
 912             (orig (marker-position eshell-last-output-end)))
 913         (goto-char eshell-last-output-end)
 914         (delete-region (point) (point-max))
 915         (when (and text (> (length text) 0))
 916           (insert text)
 917           (put-text-property (1- (point)) (point)
 918                              'last-search-pos before)
 919           (set-marker eshell-last-output-end orig)
 920           (goto-char eshell-last-output-end))))))
 921
 922 (defun eshell-prepare-for-search ()
 923   "Make sure the old history file is at the beginning of the buffer."
 924   (unless (get-text-property (point-min) 'history)
 925     (save-excursion
 926       (goto-char (point-min))
 927       (let ((end (copy-marker (point) t)))
 928         (insert-file-contents eshell-history-file-name)
 929         (set-text-properties (point-min) end
 930                              '(history t invisible t))))))
 931
 932 (defun eshell-isearch-backward (&optional invert)
 933   "Do incremental regexp search backward through past commands."
 934   (interactive)
 935   (let ((inhibit-read-only t) end)
 936     (eshell-prepare-for-search)
 937     (goto-char (point-max))
 938     (set-marker eshell-last-output-end (point))
 939     (delete-region (point) (point-max)))
 940   (isearch-mode invert t 'eshell-return-to-prompt))
 941
 942 (defun eshell-isearch-repeat-backward (&optional invert)
 943   "Do incremental regexp search backward through past commands."
 944   (interactive)
 945   (let ((old-pos (get-text-property (1- (point-max))
 946                                     'last-search-pos)))
 947     (when old-pos
 948       (goto-char old-pos)
 949       (if invert
 950           (end-of-line)
 951         (backward-char)))
 952     (setq isearch-forward invert)
 953     (isearch-search-and-update)))
 954
 955 (defun eshell-isearch-forward ()
 956   "Do incremental regexp search backward through past commands."
 957   (interactive)
 958   (eshell-isearch-backward t))
 959
 960 (defun eshell-isearch-repeat-forward ()
 961   "Do incremental regexp search backward through past commands."
 962   (interactive)
 963   (eshell-isearch-repeat-backward t))
 964
 965 (defun eshell-isearch-cancel ()
 966   (interactive)
 967   (goto-char eshell-last-output-end)
 968   (delete-region (point) (point-max))
 969   (call-interactively 'isearch-cancel))
 970
 971 (defun eshell-isearch-abort ()
 972   (interactive)
 973   (goto-char eshell-last-output-end)
 974   (delete-region (point) (point-max))
 975   (call-interactively 'isearch-abort))
 976
 977 (defun eshell-isearch-delete-char ()
 978   (interactive)
 979   (save-excursion
 980   (isearch-delete-char)))
 981
 982 (defun eshell-isearch-return ()
 983   (interactive)
 984   (isearch-done)
 985   (eshell-send-input))
 986
 987 ;;; em-hist.el ends here