iconv/iconv_open.c

   1 /* Get descriptor for character set conversion.
   2    Copyright (C) 1997,1998,1999,2000,2001,2007 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <iconv.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include <gconv_int.h>
  27 #include "gconv_charset.h"
  28
  29
  30 iconv_t
  31 iconv_open (const char *tocode, const char *fromcode)
  32 {
  33   char *tocode_conv;
  34   char *fromcode_conv;
  35   size_t tocode_len;
  36   size_t fromcode_len;
  37   __gconv_t cd;
  38   int res;
  39
  40   /* Normalize the name.  We remove all characters beside alpha-numeric,
  41      '_', '-', '/', '.', and ':'.  */
  42   tocode_len = strlen (tocode);
  43   tocode_conv = (char *) alloca (tocode_len + 3);
  44   strip (tocode_conv, tocode);
  45   tocode = (tocode_conv[2] == '\0' && tocode[0] != '\0'
  46             ? upstr (tocode_conv, tocode) : tocode_conv);
  47
  48   fromcode_len = strlen (fromcode);
  49   fromcode_conv = (char *) alloca (fromcode_len + 3);
  50   strip (fromcode_conv, fromcode);
  51   fromcode = (fromcode_conv[2] == '\0' && fromcode[0] != '\0'
  52               ? upstr (fromcode_conv, fromcode) : fromcode_conv);
  53
  54   res = __gconv_open (tocode, fromcode, &cd, 0);
  55
  56   if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
  57     {
  58       /* We must set the error number according to the specs.  */
  59       if (res == __GCONV_NOCONV || res == __GCONV_NODB)
  60         __set_errno (EINVAL);
  61
  62       return (iconv_t) -1;
  63     }
  64
  65   return (iconv_t) cd;
  66 }