idna.el

   1 ;;; idna.el --- Internationalizing Domain Names in Applications.
   2
   3 ;; Copyright (C) 2003  Simon Josefsson
   4 ;; Keywords: idna, idn, domain name, internationalization
   5
   6 ;; This file is part of GNU Libidn.
   7
   8 ;; GNU Libidn is free software; you can redistribute it and/or modify
   9 ;; it under the terms of the GNU General Public License as published by
  10 ;; the Free Software Foundation; either version 2, or (at your option)
  11 ;; any later version.
  12
  13 ;; GNU Libidn is distributed in the hope that it will be useful,
  14 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 ;; GNU General Public License for more details.
  17
  18 ;; You should have received a copy of the GNU General Public License
  19 ;; along with GNU Libidn; see the file COPYING.  If not, write to the
  20 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  21 ;; Boston, MA 02111-1307, USA.
  22
  23 ;;; Commentary:
  24
  25 ;; A simple wrapper around the command line "idn" utility in GNU
  26 ;; Libidn to make IDNA ToASCII and ToUnicode operations available in
  27 ;; Emacs.
  28
  29 ;; Example:
  30 ;;
  31 ;; (idna-to-ascii "räksmörgås.gnu.org")
  32 ;; => "xn--rksmrgs-5wao1o.gnu.org"
  33 ;;
  34 ;; (idna-to-ascii "www.gnu.org")
  35 ;; => "www.gnu.org"
  36 ;;
  37 ;; (idna-to-unicode "xn--rksmrgs-5wao1o.gnu.org")
  38 ;; => "räksmörgås.gnu.org"
  39 ;;
  40 ;; (idna-to-unicode "www.gnu.org")
  41 ;; => "www.gnu.org"
  42
  43 ;; Todo: Support AllowUnassigned and UseSTD3ASCIIRules somehow?
  44
  45 ;; This package is useless unless your emacs has at least partial
  46 ;; support for the UTF-8 coding system.
  47
  48 ;; Report bugs to bug-libidn@gnu.org.
  49
  50 ;;; Code:
  51
  52 (defgroup idna nil
  53   "Internationalizing Domain Names in Applications.")
  54
  55 (defcustom idna-program "idn"
  56   "Name of the GNU Libidn \"idn\" application."
  57   :type 'string
  58   :group 'idna)
  59
  60 (defcustom idna-environment '("CHARSET=UTF-8")
  61   "List of environment variable definitions prepended to `process-environment'."
  62   :type '(repeat string)
  63   :group 'idna)
  64
  65 (defcustom idna-to-ascii-parameters '("--quiet" "--idna-to-ascii")
  66   "Parameters passed to `idna-program' to invoke IDNA ToASCII mode."
  67   :type '(repeat string)
  68   :group 'idna)
  69
  70 (defcustom idna-to-unicode-parameters '("--quiet" "--idna-to-unicode")
  71   "Parameters passed `idna-program' to invoke IDNA ToUnicode mode."
  72   :type '(repeat string)
  73   :group 'idna)
  74
  75 ;; Internal process handling:
  76
  77 (defvar idna-to-ascii-process nil
  78   "Internal variable holding process for ToASCII.")
  79 (defvar idna-to-ascii-response nil
  80   "Internal variable holding response data received from ToASCII process.")
  81
  82 (defun idna-to-ascii-response-clear ()
  83   (setq idna-to-ascii-response nil))
  84
  85 (defun idna-to-ascii-response ()
  86   (while (and (eq (process-status idna-to-ascii-process) 'run)
  87               (null idna-to-ascii-response))
  88     (accept-process-output idna-to-ascii-process 1))
  89   idna-to-ascii-response)
  90
  91 (defun idna-to-ascii-filter (process string)
  92   (setq idna-to-ascii-response (concat idna-to-ascii-response string)))
  93
  94 (defun idna-to-ascii-process ()
  95   (if (and idna-to-ascii-process
  96            (eq (process-status idna-to-ascii-process) 'run))
  97       idna-to-ascii-process
  98     (if idna-to-ascii-process
  99         (condition-case ()
 100             (kill-process idna-to-ascii-process)
 101           (error)))
 102     (when (setq idna-to-ascii-process
 103                 (let ((process-environment (append process-environment
 104                                                    idna-environment)))
 105                   (apply 'start-process "idna" nil idna-program
 106                          idna-to-ascii-parameters)))
 107       (set-process-filter idna-to-ascii-process 'idna-to-ascii-filter)
 108       (set-process-coding-system idna-to-ascii-process 'utf-8 'utf-8)
 109       (process-kill-without-query idna-to-ascii-process))
 110     idna-to-ascii-process))
 111
 112 (defvar idna-to-unicode-process nil
 113   "Internal variable holding process for ToASCII.")
 114 (defvar idna-to-unicode-response nil
 115   "Internal variable holding response data received from ToASCII process.")
 116
 117 (defun idna-to-unicode-response-clear ()
 118   (setq idna-to-unicode-response nil))
 119
 120 (defun idna-to-unicode-response ()
 121   (while (and (eq (process-status idna-to-unicode-process) 'run)
 122               (null idna-to-unicode-response))
 123     (accept-process-output idna-to-unicode-process 1))
 124   idna-to-unicode-response)
 125
 126 (defun idna-to-unicode-filter (process string)
 127   (setq idna-to-unicode-response (concat idna-to-unicode-response string)))
 128
 129 (defun idna-to-unicode-process ()
 130   (if (and idna-to-unicode-process
 131            (eq (process-status idna-to-unicode-process) 'run))
 132       idna-to-unicode-process
 133     (if idna-to-unicode-process
 134         (condition-case ()
 135             (kill-process idna-to-unicode-process)
 136           (error)))
 137     (when (setq idna-to-unicode-process
 138                 (let ((process-environment (append process-environment
 139                                                    idna-environment)))
 140                   (apply 'start-process "idna" nil idna-program
 141                          idna-to-unicode-parameters)))
 142       (set-process-filter idna-to-unicode-process 'idna-to-unicode-filter)
 143       (set-process-coding-system idna-to-unicode-process 'utf-8 'utf-8)
 144       (process-kill-without-query idna-to-unicode-process))
 145     idna-to-unicode-process))
 146
 147 ;; IDNA Elisp API:
 148
 149 (defun idna-to-ascii (str)
 150   "Returns an ASCII Compatible Encoding (ACE) of STR.
 151 It is computed by the IDNA ToASCII operation, after converting the
 152 input to UTF-8."
 153   (let ((proc (idna-to-ascii-process))
 154         string)
 155     (if (null proc)
 156         (error "Cannot start idn application (to-ascii)")
 157       (idna-to-ascii-response-clear)
 158       (process-send-string proc (concat str "\n"))
 159       (setq string (idna-to-ascii-response))
 160       (if (and string (string= (substring string (1- (length string))) "\n"))
 161           (substring string 0 (1- (length string)))
 162         string))))
 163
 164 (defun idna-to-unicode (str)
 165   "Returns a possibly multibyte string after decoding STR.
 166 It is computed by the IDNA ToUnicode operation."
 167   (let ((proc (idna-to-unicode-process))
 168         string)
 169     (if (null proc)
 170         (error "Cannot start idn application (to-unicode)")
 171       (idna-to-unicode-response-clear)
 172       (process-send-string proc (concat str "\n"))
 173       (setq string (idna-to-unicode-response))
 174       (if (and string (string= (substring string (1- (length string))) "\n"))
 175           (substring string 0 (1- (length string)))
 176         string))))
 177
 178 (provide 'idna)
 179
 180 ;;; idna.el ends here