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Diffstat (limited to 'lisp/eshell/em-alias.el')
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diff --git a/lisp/eshell/em-alias.el b/lisp/eshell/em-alias.el new file mode 100644 index 00000000000..84ab339584f --- /dev/null +++ b/lisp/eshell/em-alias.el @@ -0,0 +1,270 @@ +;;; em-alias --- creation and management of command aliases + +;; Copyright (C) 1999, 2000 Free Sofware Foundation + +;; 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 2, 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., 59 Temple Place - Suite 330, +;; Boston, MA 02111-1307, USA. + +(provide 'em-alias) + +(eval-when-compile (require 'esh-maint)) + +(defgroup eshell-alias nil + "Command aliases allow for easy definition of alternate commands." + :tag "Command aliases" + :link '(info-link "(eshell.info)Command aliases") + :group 'eshell-module) + +;;; Commentary: + +;; Command aliases greatly simplify the definition of new commands. +;; They exist as an alternative to alias functions, which are +;; otherwise quite superior, being more flexible and natural to the +;; Emacs Lisp environment (if somewhat trickier to define; [Alias +;; functions]). +;; +;;;_* Creating aliases +;; +;; The user interface is simple: type 'alias' followed by the command +;; name followed by the definition. Argument references are made +;; using '$1', '$2', etc., or '$*'. For example: +;; +;; alias ll 'ls -l $*' +;; +;; This will cause the command 'll NEWS' to be replaced by 'ls -l +;; NEWS'. This is then passed back to the command parser for +;; reparsing.{Only the command text specified in the alias definition +;; will be reparsed. Argument references (such as '$*') are handled +;; using variable values, which means that the expansion will not be +;; reparsed, but used directly.} +;; +;; To delete an alias, specify its name without a definition: +;; +;; alias ll +;; +;; Aliases are written to disk immediately after being defined or +;; deleted. The filename in which they are kept is defined by the +;; following variable: + +(defcustom eshell-aliases-file (concat eshell-directory-name "alias") + "*The file in which aliases are kept. +Whenever an alias is defined by the user, using the `alias' command, +it will be written to this file. Thus, alias definitions (and +deletions) are always permanent. This approach was chosen for the +sake of simplicity, since that's pretty much the only benefit to be +gained by using this module." + :type 'file + :group 'eshell-alias) + +;;; +;; The format of this file is quite basic. It specifies the alias +;; definitions in almost exactly the same way that the user entered +;; them, minus any argument quoting (since interpolation is not done +;; when the file is read). Hence, it is possible to add new aliases +;; to the alias file directly, using a text editor rather than the +;; `alias' command. Or, this method can be used for editing aliases +;; that have already defined. +;; +;; Here is an example of a few different aliases, and they would +;; appear in the aliases file: +;; +;; alias clean rm -fr **/.#*~ +;; alias commit cvs commit -m changes $* +;; alias ll ls -l $* +;; alias info (info) +;; alias reindex glimpseindex -o ~/Mail +;; alias compact for i in ~/Mail/**/*~*.bz2(Lk+50) { bzip2 -9v $i } +;; +;;;_* Auto-correction of bad commands +;; +;; When a user enters the same unknown command many times during a +;; session, it is likely that they are experiencing a spelling +;; difficulty associated with a certain command. To combat this, +;; Eshell will offer to automatically define an alias for that +;; mispelled command, once a given tolerance threshold has been +;; reached. + +(defcustom eshell-bad-command-tolerance 3 + "*The number of failed commands to ignore before creating an alias." + :type 'integer + :link '(custom-manual "(eshell.info)Auto-correction of bad commands") + :group 'eshell-alias) + +;;; +;; Whenever the same bad command name is encountered this many times, +;; the user will be prompted in the minibuffer to provide an alias +;; name. An alias definition will then be created which will result +;; in an equal call to the correct name. In this way, Eshell +;; gradually learns about the commands that the user mistypes +;; frequently, and will automatically correct them! +;; +;; Note that a '$*' is automatically appended at the end of the alias +;; definition, so that entering it is unnecessary when specifying the +;; corrected command name. + +;;; Code: + +(defcustom eshell-alias-load-hook '(eshell-alias-initialize) + "*A hook that gets run when `eshell-alias' is loaded." + :type 'hook + :group 'eshell-alias) + +(defvar eshell-command-aliases-list nil + "A list of command aliases currently defined by the user. +Each element of this alias is a list of the form: + + (NAME DEFINITION) + +Where NAME is the textual name of the alias, and DEFINITION is the +command string to replace that command with. + +Note: this list should not be modified in your '.emacs' file. Rather, +any desired alias definitions should be declared using the `alias' +command, which will automatically write them to the file named by +`eshell-aliases-file'.") + +(put 'eshell-command-aliases-list 'risky-local-variable t) + +(defvar eshell-failed-commands-alist nil + "An alist of command name failures.") + +(defun eshell-alias-initialize () + "Initialize the alias handling code." + (make-local-variable 'eshell-failed-commands-alist) + (make-local-hook 'eshell-alternate-command-hook) + (add-hook 'eshell-alternate-command-hook 'eshell-fix-bad-commands t t) + (eshell-read-aliases-list) + (make-local-hook 'eshell-named-command-hook) + (add-hook 'eshell-named-command-hook 'eshell-maybe-replace-by-alias t t)) + +(defun eshell/alias (&optional alias &rest definition) + "Define an ALIAS in the user's alias list using DEFINITION." + (if (not alias) + (eshell-for alias eshell-command-aliases-list + (eshell-print (apply 'format "alias %s %s\n" alias))) + (if (not definition) + (setq eshell-command-aliases-list + (delq (assoc alias eshell-command-aliases-list) + eshell-command-aliases-list)) + (and (stringp definition) + (set-text-properties 0 (length definition) nil definition)) + (let ((def (assoc alias eshell-command-aliases-list)) + (alias-def (list alias + (eshell-flatten-and-stringify definition)))) + (if def + (setq eshell-command-aliases-list + (delq def eshell-command-aliases-list))) + (setq eshell-command-aliases-list + (cons alias-def eshell-command-aliases-list)))) + (eshell-write-aliases-list)) + nil) + +(defun pcomplete/eshell-mode/alias () + "Completion function for Eshell's `alias' command." + (pcomplete-here (eshell-alias-completions pcomplete-stub))) + +(defun eshell-read-aliases-list () + "Read in an aliases list from `eshell-aliases-file'." + (let ((file eshell-aliases-file)) + (when (file-readable-p file) + (setq eshell-command-aliases-list + (with-temp-buffer + (let (eshell-command-aliases-list) + (insert-file-contents file) + (while (not (eobp)) + (if (re-search-forward + "^alias\\s-+\\(\\S-+\\)\\s-+\\(.+\\)") + (setq eshell-command-aliases-list + (cons (list (match-string 1) + (match-string 2)) + eshell-command-aliases-list))) + (forward-line 1)) + eshell-command-aliases-list)))))) + +(defun eshell-write-aliases-list () + "Write out the current aliases into `eshell-aliases-file'." + (if (file-writable-p (file-name-directory eshell-aliases-file)) + (let ((eshell-current-handles + (eshell-create-handles eshell-aliases-file 'overwrite))) + (eshell/alias) + (eshell-close-handles 0)))) + +(defsubst eshell-lookup-alias (name) + "Check whether NAME is aliased. Return the alias if there is one." + (assoc name eshell-command-aliases-list)) + +(defvar eshell-prevent-alias-expansion nil) + +(defun eshell-maybe-replace-by-alias (command args) + "If COMMAND has an alias definition, call that instead using RAGS." + (unless (and eshell-prevent-alias-expansion + (member command eshell-prevent-alias-expansion)) + (let ((alias (eshell-lookup-alias command))) + (if alias + (throw 'eshell-replace-command + (list + 'let + (list + (list 'eshell-command-name + (list 'quote eshell-last-command-name)) + (list 'eshell-command-arguments + (list 'quote eshell-last-arguments)) + (list 'eshell-prevent-alias-expansion + (list 'quote + (cons command + eshell-prevent-alias-expansion)))) + (eshell-parse-command (nth 1 alias)))))))) + +(defun eshell-alias-completions (name) + "Find all possible completions for NAME. +These are all the command aliases which begin with NAME." + (let (completions) + (eshell-for alias eshell-command-aliases-list + (if (string-match (concat "^" name) (car alias)) + (setq completions (cons (car alias) completions)))) + completions)) + +(defun eshell-fix-bad-commands (name) + "If the user repeatedly a bad command NAME, make an alias for them." + (ignore + (unless (file-name-directory name) + (let ((entry (assoc name eshell-failed-commands-alist))) + (if (not entry) + (setq eshell-failed-commands-alist + (cons (cons name 1) eshell-failed-commands-alist)) + (if (< (cdr entry) eshell-bad-command-tolerance) + (setcdr entry (1+ (cdr entry))) + (let ((alias (concat + (read-string + (format "Define alias for \"%s\": " name)) + " $*"))) + (eshell/alias name alias) + (throw 'eshell-replace-command + (list + 'let + (list + (list 'eshell-command-name + (list 'quote name)) + (list 'eshell-command-arguments + (list 'quote eshell-last-arguments)) + (list 'eshell-prevent-alias-expansion + (list 'quote + (cons name + eshell-prevent-alias-expansion)))) + (eshell-parse-command alias)))))))))) + +;;; em-alias.el ends here |