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Diffstat (limited to 'lisp/eshell/em-basic.el')
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diff --git a/lisp/eshell/em-basic.el b/lisp/eshell/em-basic.el new file mode 100644 index 00000000000..0a7e9a97573 --- /dev/null +++ b/lisp/eshell/em-basic.el @@ -0,0 +1,183 @@ +;;; em-basic --- basic shell builtin commands + +;; 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-basic) + +(eval-when-compile (require 'esh-maint)) + +(defgroup eshell-basic nil + "The \"basic\" code provides a set of convenience functions which +are traditionally considered shell builtins. Since all of the +functionality provided by them is accessible through Lisp, they are +not really builtins at all, but offer a command-oriented way to do the +same thing." + :tag "Basic shell commands" + :group 'eshell-module) + +;;; Commentary: + +;; There are very few basic Eshell commands -- so-called builtins. +;; They are: echo, umask, and version. +;; +;;;_* `echo' +;; +;; The `echo' command repeats its arguments to the screen. It is +;; optional whether this is done in a Lisp-friendly fashion (so that +;; the value of echo is useful to a Lisp command using the result of +;; echo as an argument), or whether it should try to act like a normal +;; shell echo, and always result in a flat string being returned. + +(defcustom eshell-plain-echo-behavior nil + "*If non-nil, `echo' tries to behave like an ordinary shell echo. +This comes at some detriment to Lisp functionality. However, the Lisp +equivalent of `echo' can always be achieved by using `identity'." + :type 'boolean + :group 'eshell-basic) + +;;; +;; An example of the difference is the following: +;; +;; echo Hello world +;; +;; If `eshell-plain-echo-behavior' is non-nil, this will yield the +;; string "Hello world". If Lisp behavior is enabled, however, it +;; will yield a list whose two elements are the strings "Hello" and +;; "world". The way to write an equivalent expression for both would +;; be: +;; +;; echo "Hello world" +;; +;; This always returns a single string. +;; +;;;_* `umask' +;; +;; The umask command changes the default file permissions for newly +;; created files. It uses the same syntax as bash. +;; +;;;_* `version' +;; +;; This command reports the version number for Eshell and all its +;; dependent module, including the date when those modules were last +;; modified. + +;;; Code: + +(require 'esh-opt) + +;;; Functions: + +(defun eshell-echo (args &optional output-newline) + "Implementation code for a Lisp version of `echo'. +It returns a formatted value that should be passed to `eshell-print' +or `eshell-printn' for display." + (if eshell-plain-echo-behavior + (concat (apply 'eshell-flatten-and-stringify args) "\n") + (let ((value + (cond + ((= (length args) 0) "") + ((= (length args) 1) + (car args)) + (t + (mapcar + (function + (lambda (arg) + (if (stringp arg) + (set-text-properties 0 (length arg) nil arg)) + arg)) + args))))) + (if output-newline + (cond + ((stringp value) + (concat value "\n")) + ((listp value) + (append value (list "\n"))) + (t + (concat (eshell-stringify value) "\n"))) + value)))) + +(defun eshell/echo (&rest args) + "Implementation of `echo'. See `eshell-plain-echo-behavior'." + (eshell-eval-using-options + "echo" args + '((?n nil nil output-newline "terminate with a newline") + (?h "help" nil nil "output this help screen") + :preserve-args + :usage "[-n] [object]") + (eshell-echo args output-newline))) + +(defun eshell/printnl (&rest args) + "Print out each of the argument, separated by newlines." + (let ((elems (eshell-flatten-list args))) + (while elems + (eshell-printn (eshell-echo (list (car elems)))) + (setq elems (cdr elems))))) + +(defun eshell/listify (&rest args) + "Return the argument(s) as a single list." + (if (> (length args) 1) + args + (if (listp (car args)) + (car args) + (list (car args))))) + +(defun eshell/umask (&rest args) + "Shell-like implementation of `umask'." + (eshell-eval-using-options + "umask" args + '((?S "symbolic" nil symbolic-p "display umask symbolically") + (?h "help" nil nil "display this usage message") + :usage "[-S] [mode]") + (if (or (not args) symbolic-p) + (let ((modstr + (concat "000" + (format "%o" + (logand (lognot (default-file-modes)) + 511))))) + (setq modstr (substring modstr (- (length modstr) 3))) + (when symbolic-p + (let ((mode (default-file-modes))) + (setq modstr + (format + "u=%s,g=%s,o=%s" + (concat (and (= (logand mode 64) 64) "r") + (and (= (logand mode 128) 128) "w") + (and (= (logand mode 256) 256) "x")) + (concat (and (= (logand mode 8) 8) "r") + (and (= (logand mode 16) 16) "w") + (and (= (logand mode 32) 32) "x")) + (concat (and (= (logand mode 1) 1) "r") + (and (= (logand mode 2) 2) "w") + (and (= (logand mode 4) 4) "x")))))) + (eshell-printn modstr)) + (setcar args (eshell-convert (car args))) + (if (numberp (car args)) + (set-default-file-modes + (- 511 (car (read-from-string + (concat "?\\" (number-to-string (car args))))))) + (error "setting umask symbolically is not yet implemented")) + (eshell-print + "Warning: umask changed for all new files created by Emacs.\n")) + nil)) + +(eval-when-compile + (defvar print-func)) + +;;; em-basic.el ends here |