root/trunk/lisp/eshell/em-unix.el

;;; em-unix.el --- UNIX command aliases

;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004,
;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Author: John Wiegley <johnw@gnu.org>

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

(provide 'em-unix)

(eval-when-compile (require 'esh-maint))
(require 'eshell)

(defgroup eshell-unix nil
  "This module defines many of the more common UNIX utilities as
aliases implemented in Lisp.  These include mv, ln, cp, rm, etc.  If
the user passes arguments which are too complex, or are unrecognized
by the Lisp variant, the external version will be called (if
available).  The only reason not to use them would be because they are
usually much slower.  But in several cases their tight integration
with Eshell makes them more versatile than their traditional cousins
\(such as being able to use `kill' to kill Eshell background processes
by name)."
  :tag "UNIX commands in Lisp"
  :group 'eshell-module)

;;; Commentary:

;; This file contains implementations of several UNIX command in Emacs
;; Lisp, for several reasons:
;;
;;   1) it makes them available on all platforms where the Lisp
;;      functions used are available
;;
;;   2) it makes their functionality accessible and modified by the
;;      Lisp programmer.
;;
;;   3) it allows Eshell to refrain from having to invoke external
;;      processes for common operations.

(defcustom eshell-unix-load-hook '(eshell-unix-initialize)
  "*A list of functions to run when `eshell-unix' is loaded."
  :type 'hook
  :group 'eshell-unix)

(defcustom eshell-plain-grep-behavior nil
  "*If non-nil, standalone \"grep\" commands will behave normally.
Standalone in this context means not redirected, and not on the
receiving side of a command pipeline."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-no-grep-available (not (eshell-search-path "grep"))
  "*If non-nil, no grep is available on the current machine."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-plain-diff-behavior nil
  "*If non-nil, standalone \"diff\" commands will behave normally.
Standalone in this context means not redirected, and not on the
receiving side of a command pipeline."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-plain-locate-behavior (eshell-under-xemacs-p)
  "*If non-nil, standalone \"locate\" commands will behave normally.
Standalone in this context means not redirected, and not on the
receiving side of a command pipeline."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-rm-removes-directories nil
  "*If non-nil, `rm' will remove directory entries.
Otherwise, `rmdir' is required."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-rm-interactive-query (= (user-uid) 0)
  "*If non-nil, `rm' will query before removing anything."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-mv-interactive-query (= (user-uid) 0)
  "*If non-nil, `mv' will query before overwriting anything."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-mv-overwrite-files t
  "*If non-nil, `mv' will overwrite files without warning."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-cp-interactive-query (= (user-uid) 0)
  "*If non-nil, `cp' will query before overwriting anything."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-cp-overwrite-files t
  "*If non-nil, `cp' will overwrite files without warning."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-ln-interactive-query (= (user-uid) 0)
  "*If non-nil, `ln' will query before overwriting anything."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-ln-overwrite-files nil
  "*If non-nil, `ln' will overwrite files without warning."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-default-target-is-dot nil
  "*If non-nil, the default destination for cp, mv or ln is `.'."
  :type 'boolean
  :group 'eshell-unix)

(defcustom eshell-du-prefer-over-ange nil
  "*Use Eshell's du in ange-ftp remote directories.
Otherwise, Emacs will attempt to use rsh to invoke du on the remote machine."
  :type 'boolean
  :group 'eshell-unix)

(require 'esh-opt)

;;; Functions:

(defun eshell-unix-initialize ()
  "Initialize the UNIX support/emulation code."
  (when (eshell-using-module 'eshell-cmpl)
    (add-hook 'pcomplete-try-first-hook
              'eshell-complete-host-reference nil t))
  (make-local-variable 'eshell-complex-commands)
  (setq eshell-complex-commands
        (append '("grep" "egrep" "fgrep" "agrep" "glimpse" "locate"
                  "cat" "time" "cp" "mv" "make" "du" "diff")
                eshell-complex-commands)))

(defalias 'eshell/date     'current-time-string)
(defalias 'eshell/basename 'file-name-nondirectory)
(defalias 'eshell/dirname  'file-name-directory)

(eval-when-compile
  (defvar interactive)
  (defvar preview)
  (defvar recursive)
  (defvar verbose))

(defun eshell/man (&rest args)
  "Invoke man, flattening the arguments appropriately."
  (funcall 'man (apply 'eshell-flatten-and-stringify args)))

(put 'eshell/man 'eshell-no-numeric-conversions t)

(defun eshell-remove-entries (path files &optional top-level)
  "From PATH, remove all of the given FILES, perhaps interactively."
  (while files
    (if (string-match "\\`\\.\\.?\\'"
                      (file-name-nondirectory (car files)))
        (if top-level
            (eshell-error "rm: cannot remove `.' or `..'\n"))
      (if (and (file-directory-p (car files))
               (not (file-symlink-p (car files))))
          (let ((dir (file-name-as-directory (car files))))
            (eshell-remove-entries dir
                                   (mapcar
                                    (function
                                     (lambda (file)
                                       (concat dir file)))
                                    (directory-files dir)))
            (if verbose
                (eshell-printn (format "rm: removing directory `%s'"
                                       (car files))))
            (unless
                (or preview
                    (and interactive
                         (not (y-or-n-p
                               (format "rm: remove directory `%s'? "
                                       (car files))))))
              (eshell-funcalln 'delete-directory (car files))))
        (if verbose
            (eshell-printn (format "rm: removing file `%s'"
                                   (car files))))
        (unless (or preview
                    (and interactive
                         (not (y-or-n-p
                               (format "rm: remove `%s'? "
                                       (car files))))))
          (eshell-funcalln 'delete-file (car files)))))
    (setq files (cdr files))))

(defun eshell/rm (&rest args)
  "Implementation of rm in Lisp.
This is implemented to call either `delete-file', `kill-buffer',
`kill-process', or `unintern', depending on the nature of the
argument."
  (setq args (eshell-flatten-list args))
  (eshell-eval-using-options
   "rm" args
   '((?h "help" nil nil "show this usage screen")
     (?f "force" nil force-removal "force removal")
     (?i "interactive" nil interactive "prompt before any removal")
     (?n "preview" nil preview "don't change anything on disk")
     (?r "recursive" nil recursive
         "remove the contents of directories recursively")
     (?R nil nil recursive "(same)")
     (?v "verbose" nil verbose "explain what is being done")
     :preserve-args
     :external "rm"
     :show-usage
     :usage "[OPTION]... FILE...
Remove (unlink) the FILE(s).")
   (unless interactive
     (setq interactive eshell-rm-interactive-query))
   (if (and force-removal interactive)
       (setq interactive nil))
   (while args
     (let ((entry (if (stringp (car args))
                      (directory-file-name (car args))
                    (if (numberp (car args))
                        (number-to-string (car args))
                      (car args)))))
       (cond
        ((bufferp entry)
         (if verbose
             (eshell-printn (format "rm: removing buffer `%s'" entry)))
         (unless (or preview
                     (and interactive
                          (not (y-or-n-p (format "rm: delete buffer `%s'? "
                                                 entry)))))
           (eshell-funcalln 'kill-buffer entry)))
        ((eshell-processp entry)
         (if verbose
             (eshell-printn (format "rm: killing process `%s'" entry)))
         (unless (or preview
                     (and interactive
                          (not (y-or-n-p (format "rm: kill process `%s'? "
                                                 entry)))))
           (eshell-funcalln 'kill-process entry)))
        ((symbolp entry)
         (if verbose
             (eshell-printn (format "rm: uninterning symbol `%s'" entry)))
         (unless
             (or preview
                 (and interactive
                      (not (y-or-n-p (format "rm: unintern symbol `%s'? "
                                             entry)))))
           (eshell-funcalln 'unintern entry)))
        ((stringp entry)
         (if (and (file-directory-p entry)
                  (not (file-symlink-p entry)))
             (if (or recursive
                     eshell-rm-removes-directories)
                 (if (or preview
                         (not interactive)
                         (y-or-n-p
                          (format "rm: descend into directory `%s'? "
                                  entry)))
                     (eshell-remove-entries nil (list entry) t))
               (eshell-error (format "rm: %s: is a directory\n" entry)))
           (eshell-remove-entries nil (list entry) t)))))
     (setq args (cdr args)))
   nil))

(put 'eshell/rm 'eshell-no-numeric-conversions t)

(defun eshell/mkdir (&rest args)
  "Implementation of mkdir in Lisp."
  (eshell-eval-using-options
   "mkdir" args
   '((?h "help" nil nil "show this usage screen")
     :external "mkdir"
     :show-usage
     :usage "[OPTION] DIRECTORY...
Create the DIRECTORY(ies), if they do not already exist.")
   (while args
     (eshell-funcalln 'make-directory (car args))
     (setq args (cdr args)))
   nil))

(put 'eshell/mkdir 'eshell-no-numeric-conversions t)

(defun eshell/rmdir (&rest args)
  "Implementation of rmdir in Lisp."
  (eshell-eval-using-options
   "rmdir" args
   '((?h "help" nil nil "show this usage screen")
     :external "rmdir"
     :show-usage
     :usage "[OPTION] DIRECTORY...
Remove the DIRECTORY(ies), if they are empty.")
   (while args
     (eshell-funcalln 'delete-directory (car args))
     (setq args (cdr args)))
   nil))

(put 'eshell/rmdir 'eshell-no-numeric-conversions t)

(eval-when-compile
  (defvar no-dereference)
  (defvar preview)
  (defvar verbose))

(defvar eshell-warn-dot-directories t)

(defun eshell-shuffle-files (command action files target func deep &rest args)
  "Shuffle around some filesystem entries, using FUNC to do the work."
  (let ((attr-target (eshell-file-attributes target))
        (is-dir (or (file-directory-p target)
                    (and preview (not eshell-warn-dot-directories))))
        attr)
    (if (and (not preview) (not is-dir)
             (> (length files) 1))
        (error "%s: when %s multiple files, last argument must be a directory"
               command action))
    (while files
      (setcar files (directory-file-name (car files)))
      (cond
       ((string-match "\\`\\.\\.?\\'"
                      (file-name-nondirectory (car files)))
        (if eshell-warn-dot-directories
            (eshell-error (format "%s: %s: omitting directory\n"
                                  command (car files)))))
       ((and attr-target
             (or (not (eshell-under-windows-p))
                 (eq system-type 'ms-dos))
             (setq attr (eshell-file-attributes (car files)))
             (nth 10 attr-target) (nth 10 attr)
             ;; Use equal, not -, since the inode and the device could
             ;; cons cells.
             (equal (nth 10 attr-target) (nth 10 attr))
             (nth 11 attr-target) (nth 11 attr)
             (equal (nth 11 attr-target) (nth 11 attr)))
        (eshell-error (format "%s: `%s' and `%s' are the same file\n"
                              command (car files) target)))
       (t
        (let ((source (car files))
              (target (if is-dir
                          (expand-file-name
                           (file-name-nondirectory (car files)) target)
                        target))
              link)
          (if (and (file-directory-p source)
                   (or (not no-dereference)
                       (not (file-symlink-p source)))
                   (not (memq func '(make-symbolic-link
                                     add-name-to-file))))
              (if (and (eq func 'copy-file)
                       (not recursive))
                  (eshell-error (format "%s: %s: omitting directory\n"
                                        command (car files)))
                (let (eshell-warn-dot-directories)
                  (if (and (not deep)
                           (eq func 'rename-file)
                           ;; Use equal, since the device might be a
                           ;; cons cell.
                           (equal (nth 11 (eshell-file-attributes
                                           (file-name-directory
                                            (directory-file-name
                                             (expand-file-name source)))))
                                  (nth 11 (eshell-file-attributes
                                           (file-name-directory
                                            (directory-file-name
                                             (expand-file-name target)))))))
                      (apply 'eshell-funcalln func source target args)
                  (unless (file-directory-p target)
                    (if verbose
                        (eshell-printn
                         (format "%s: making directory %s"
                                 command target)))
                    (unless preview
                      (eshell-funcalln 'make-directory target)))
                  (apply 'eshell-shuffle-files
                         command action
                         (mapcar
                          (function
                           (lambda (file)
                             (concat source "/" file)))
                          (directory-files source))
                         target func t args)
                  (when (eq func 'rename-file)
                    (if verbose
                        (eshell-printn
                         (format "%s: deleting directory %s"
                                 command source)))
                    (unless preview
                      (eshell-funcalln 'delete-directory source))))))
            (if verbose
                (eshell-printn (format "%s: %s -> %s" command
                                       source target)))
            (unless preview
              (if (and no-dereference
                       (setq link (file-symlink-p source)))
                  (progn
                    (apply 'eshell-funcalln 'make-symbolic-link
                           link target args)
                    (if (eq func 'rename-file)
                        (if (and (file-directory-p source)
                                 (not (file-symlink-p source)))
                            (eshell-funcalln 'delete-directory source)
                          (eshell-funcalln 'delete-file source))))
                (apply 'eshell-funcalln func source target args)))))))
      (setq files (cdr files)))))

(defun eshell-shorthand-tar-command (command args)
  "Rewrite `cp -v dir a.tar.gz' to `tar cvzf a.tar.gz dir'."
  (let* ((archive (car (last args)))
         (tar-args
          (cond ((string-match "z2" archive) "If")
                ((string-match "gz" archive) "zf")
                ((string-match "\\(az\\|Z\\)" archive) "Zf")
                (t "f"))))
    (if (file-exists-p archive)
        (setq tar-args (concat "u" tar-args))
      (setq tar-args (concat "c" tar-args)))
    (if verbose
        (setq tar-args (concat "v" tar-args)))
    (if (equal command "mv")
        (setq tar-args (concat "--remove-files -" tar-args)))
    ;; truncate the archive name from the arguments
    (setcdr (last args 2) nil)
    (throw 'eshell-replace-command
           (eshell-parse-command
            (format "tar %s %s" tar-args archive) args))))

;; this is to avoid duplicating code...
(defmacro eshell-mvcpln-template (command action func query-var
                                          force-var &optional preserve)
  `(let ((len (length args)))
     (if (or (= len 0)
             (and (= len 1) (null eshell-default-target-is-dot)))
         (error "%s: missing destination file or directory" ,command))
     (if (= len 1)
         (nconc args '(".")))
     (setq args (eshell-stringify-list (eshell-flatten-list args)))
     (if (and ,(not (equal command "ln"))
              (string-match eshell-tar-regexp (car (last args)))
              (or (> (length args) 2)
                  (and (file-directory-p (car args))
                       (or (not no-dereference)
                           (not (file-symlink-p (car args)))))))
         (eshell-shorthand-tar-command ,command args)
       (let ((target (car (last args)))
             ange-cache)
         (setcdr (last args 2) nil)
         (eshell-shuffle-files
          ,command ,action args target ,func nil
          ,@(append
             `((if (and (or interactive
                            ,query-var)
                        (not force))
                   1 (or force ,force-var)))
             (if preserve
                 (list preserve)))))
       nil)))

(defun eshell/mv (&rest args)
  "Implementation of mv in Lisp."
  (eshell-eval-using-options
   "mv" args
   '((?f "force" nil force
         "remove existing destinations, never prompt")
     (?i "interactive" nil interactive
         "request confirmation if target already exists")
     (?n "preview" nil preview
         "don't change anything on disk")
     (?v "verbose" nil verbose
         "explain what is being done")
     (nil "help" nil nil "show this usage screen")
     :preserve-args
     :external "mv"
     :show-usage
     :usage "[OPTION]... SOURCE DEST
   or: mv [OPTION]... SOURCE... DIRECTORY
Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.
\[OPTION] DIRECTORY...")
   (let ((no-dereference t))
     (eshell-mvcpln-template "mv" "moving" 'rename-file
                             eshell-mv-interactive-query
                             eshell-mv-overwrite-files))))

(put 'eshell/mv 'eshell-no-numeric-conversions t)

(defun eshell/cp (&rest args)
  "Implementation of cp in Lisp."
  (eshell-eval-using-options
   "cp" args
   '((?a "archive" nil archive
         "same as -dpR")
     (?d "no-dereference" nil no-dereference
         "preserve links")
     (?f "force" nil force
         "remove existing destinations, never prompt")
     (?i "interactive" nil interactive
         "request confirmation if target already exists")
     (?n "preview" nil preview
         "don't change anything on disk")
     (?p "preserve" nil preserve
         "preserve file attributes if possible")
     (?R "recursive" nil recursive
         "copy directories recursively")
     (?v "verbose" nil verbose
         "explain what is being done")
     (nil "help" nil nil "show this usage screen")
     :preserve-args
     :external "cp"
     :show-usage
     :usage "[OPTION]... SOURCE DEST
   or:  cp [OPTION]... SOURCE... DIRECTORY
Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY.")
   (if archive
       (setq preserve t no-dereference t recursive t))
   (eshell-mvcpln-template "cp" "copying" 'copy-file
                           eshell-cp-interactive-query
                           eshell-cp-overwrite-files preserve)))

(put 'eshell/cp 'eshell-no-numeric-conversions t)

(defun eshell/ln (&rest args)
  "Implementation of ln in Lisp."
  (eshell-eval-using-options
   "ln" args
   '((?h "help" nil nil "show this usage screen")
     (?s "symbolic" nil symbolic
         "make symbolic links instead of hard links")
     (?i "interactive" nil interactive
         "request confirmation if target already exists")
     (?f "force" nil force "remove existing destinations, never prompt")
     (?n "preview" nil preview
         "don't change anything on disk")
     (?v "verbose" nil verbose "explain what is being done")
     :preserve-args
     :external "ln"
     :show-usage
     :usage "[OPTION]... TARGET [LINK_NAME]
   or:  ln [OPTION]... TARGET... DIRECTORY
Create a link to the specified TARGET with optional LINK_NAME.  If there is
more than one TARGET, the last argument must be a directory;  create links
in DIRECTORY to each TARGET.  Create hard links by default, symbolic links
with '--symbolic'.  When creating hard links, each TARGET must exist.")
   (let ((no-dereference t))
     (eshell-mvcpln-template "ln" "linking"
                             (if symbolic
                                 'make-symbolic-link
                               'add-name-to-file)
                             eshell-ln-interactive-query
                             eshell-ln-overwrite-files))))

(put 'eshell/ln 'eshell-no-numeric-conversions t)

(defun eshell/cat (&rest args)
  "Implementation of cat in Lisp.
If in a pipeline, or the file is not a regular file, directory or
symlink, then revert to the system's definition of cat."
  (setq args (eshell-stringify-list (eshell-flatten-list args)))
  (if (or eshell-in-pipeline-p
          (catch 'special
            (eshell-for arg args
              (unless (or (and (stringp arg)
                               (> (length arg) 0)
                               (eq (aref arg 0) ?-))
                          (let ((attrs (eshell-file-attributes arg)))
                            (and attrs (memq (aref (nth 8 attrs) 0)
                                             '(?d ?l ?-)))))
                (throw 'special t)))))
      (let ((ext-cat (eshell-search-path "cat")))
        (if ext-cat
            (throw 'eshell-replace-command
                   (eshell-parse-command ext-cat args))
          (if eshell-in-pipeline-p
              (error "Eshell's `cat' does not work in pipelines")
            (error "Eshell's `cat' cannot display one of the files given"))))
    (eshell-init-print-buffer)
    (eshell-eval-using-options
     "cat" args
     '((?h "help" nil nil "show this usage screen")
       :external "cat"
       :show-usage
       :usage "[OPTION] FILE...
Concatenate FILE(s), or standard input, to standard output.")
     (eshell-for file args
       (if (string= file "-")
           (throw 'eshell-external
                  (eshell-external-command "cat" args))))
     (let ((curbuf (current-buffer)))
       (eshell-for file args
         (with-temp-buffer
           (insert-file-contents file)
           (goto-char (point-min))
           (while (not (eobp))
             (let ((str (buffer-substring
                         (point) (min (1+ (line-end-position))
                                      (point-max)))))
               (with-current-buffer curbuf
                 (eshell-buffered-print str)))
             (forward-line)))))
     (eshell-flush)
     ;; if the file does not end in a newline, do not emit one
     (setq eshell-ensure-newline-p nil))))

(put 'eshell/cat 'eshell-no-numeric-conversions t)

;; special front-end functions for compilation-mode buffers

(defun eshell/make (&rest args)
  "Use `compile' to do background makes."
  (if (and eshell-current-subjob-p
           (eshell-interactive-output-p))
      (let ((compilation-process-setup-function
             (list 'lambda nil
                   (list 'setq 'process-environment
                         (list 'quote (eshell-copy-environment))))))
        (compile (concat "make " (eshell-flatten-and-stringify args))))
    (throw 'eshell-replace-command
           (eshell-parse-command "*make" (eshell-stringify-list
                                          (eshell-flatten-list args))))))

(put 'eshell/make 'eshell-no-numeric-conversions t)

(defun eshell-occur-mode-goto-occurrence ()
  "Go to the occurrence the current line describes."
  (interactive)
  (let ((pos (occur-mode-find-occurrence)))
    (pop-to-buffer (marker-buffer pos))
    (goto-char (marker-position pos))))

(defun eshell-occur-mode-mouse-goto (event)
  "In Occur mode, go to the occurrence whose line you click on."
  (interactive "e")
  (let (pos)
    (save-excursion
      (set-buffer (window-buffer (posn-window (event-end event))))
      (save-excursion
        (goto-char (posn-point (event-end event)))
        (setq pos (occur-mode-find-occurrence))))
    (pop-to-buffer (marker-buffer pos))
    (goto-char (marker-position pos))))

(defun eshell-poor-mans-grep (args)
  "A poor version of grep that opens every file and uses `occur'.
This eats up memory, since it leaves the buffers open (to speed future
searches), and it's very slow.  But, if your system has no grep
available..."
  (save-selected-window
    (let ((default-dir default-directory))
      (with-current-buffer (get-buffer-create "*grep*")
        (let ((inhibit-read-only t)
              (default-directory default-dir))
          (erase-buffer)
          (occur-mode)
          (let ((files (eshell-stringify-list
                        (eshell-flatten-list (cdr args))))
                (inhibit-redisplay t)
                string)
            (when (car args)
              (if (get-buffer "*Occur*")
                  (kill-buffer (get-buffer "*Occur*")))
              (setq string nil)
              (while files
                (with-current-buffer (find-file-noselect (car files))
                  (save-excursion
                    (ignore-errors
                      (occur (car args))))
                  (if (get-buffer "*Occur*")
                      (with-current-buffer (get-buffer "*Occur*")
                        (setq string (buffer-string))
                        (kill-buffer (current-buffer)))))
                (if string (insert string))
                (setq string nil
                      files (cdr files)))))
          (local-set-key [mouse-2] 'eshell-occur-mode-mouse-goto)
          (local-set-key [(control ?c) (control ?c)]
                         'eshell-occur-mode-goto-occurrence)
          (local-set-key [(control ?m)]
                         'eshell-occur-mode-goto-occurrence)
          (local-set-key [return] 'eshell-occur-mode-goto-occurrence)
          (pop-to-buffer (current-buffer) t)
          (goto-char (point-min))
          (resize-temp-buffer-window))))))

(defun eshell-grep (command args &optional maybe-use-occur)
  "Generic service function for the various grep aliases.
It calls Emacs' grep utility if the command is not redirecting output,
and if it's not part of a command pipeline.  Otherwise, it calls the
external command."
  (if (and maybe-use-occur eshell-no-grep-available)
      (eshell-poor-mans-grep args)
    (if (or eshell-plain-grep-behavior
            (not (and (eshell-interactive-output-p)
                      (not eshell-in-pipeline-p)
                      (not eshell-in-subcommand-p))))
        (throw 'eshell-replace-command
               (eshell-parse-command (concat "*" command)
                                     (eshell-stringify-list
                                      (eshell-flatten-list args))))
      (let* ((args (mapconcat 'identity
                              (mapcar 'shell-quote-argument
                                      (eshell-stringify-list
                                       (eshell-flatten-list args)))
                              " "))
             (cmd (progn
                    (set-text-properties 0 (length args)
                                         '(invisible t) args)
                    (format "%s -n %s" command args)))
             compilation-scroll-output)
        (grep cmd)))))

(defun eshell/grep (&rest args)
  "Use Emacs grep facility instead of calling external grep."
  (eshell-grep "grep" args t))

(defun eshell/egrep (&rest args)
  "Use Emacs grep facility instead of calling external egrep."
  (eshell-grep "egrep" args t))

(defun eshell/fgrep (&rest args)
  "Use Emacs grep facility instead of calling external fgrep."
  (eshell-grep "fgrep" args t))

(defun eshell/agrep (&rest args)
  "Use Emacs grep facility instead of calling external agrep."
  (eshell-grep "agrep" args))

(defun eshell/glimpse (&rest args)
  "Use Emacs grep facility instead of calling external glimpse."
  (let (null-device)
    (eshell-grep "glimpse" (append '("-z" "-y") args))))

;; completions rules for some common UNIX commands

(defsubst eshell-complete-hostname ()
  "Complete a command that wants a hostname for an argument."
  (pcomplete-here (eshell-read-host-names)))

(defun eshell-complete-host-reference ()
  "If there is a host reference, complete it."
  (let ((arg (pcomplete-actual-arg))
        index)
    (when (setq index (string-match "@[a-z.]*\\'" arg))
      (setq pcomplete-stub (substring arg (1+ index))
            pcomplete-last-completion-raw t)
      (throw 'pcomplete-completions (eshell-read-host-names)))))

(defalias 'pcomplete/ftp    'eshell-complete-hostname)
(defalias 'pcomplete/ncftp  'eshell-complete-hostname)
(defalias 'pcomplete/ping   'eshell-complete-hostname)
(defalias 'pcomplete/rlogin 'eshell-complete-hostname)

(defun pcomplete/telnet ()
  (require 'pcmpl-unix)
  (pcomplete-opt "xl(pcmpl-unix-user-names)")
  (eshell-complete-hostname))

(defun pcomplete/rsh ()
  "Complete `rsh', which, after the user and hostname, is like xargs."
  (require 'pcmpl-unix)
  (pcomplete-opt "l(pcmpl-unix-user-names)")
  (eshell-complete-hostname)
  (pcomplete-here (funcall pcomplete-command-completion-function))
  (funcall (or (pcomplete-find-completion-function (pcomplete-arg 1))
               pcomplete-default-completion-function)))

(defalias 'pcomplete/ssh 'pcomplete/rsh)

(eval-when-compile
  (defvar block-size)
  (defvar by-bytes)
  (defvar dereference-links)
  (defvar grand-total)
  (defvar human-readable)
  (defvar max-depth)
  (defvar only-one-filesystem)
  (defvar show-all))

(defsubst eshell-du-size-string (size)
  (let* ((str (eshell-printable-size size human-readable block-size t))
         (len (length str)))
    (concat str (if (< len 8)
                    (make-string (- 8 len) ? )))))

(defun eshell-du-sum-directory (path depth)
  "Summarize PATH, and its member directories."
  (let ((entries (eshell-directory-files-and-attributes path))
        (size 0.0))
&nb