iconv/iconv_open.c

   1 /* Get descriptor for character set conversion.
   2    Copyright (C) 1997-2021 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, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <alloca.h>
  21 #include <errno.h>
  22 #include <iconv.h>
  23 #include <stdbool.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include <gconv_int.h>
  28 #include "gconv_charset.h"
  29
  30
  31 iconv_t
  32 iconv_open (const char *tocode, const char *fromcode)
  33 {
  34   __gconv_t cd;
  35   struct gconv_spec conv_spec;
  36
  37   if (__gconv_create_spec (&conv_spec, fromcode, tocode) == NULL)
  38     return (iconv_t) -1;
  39
  40   int res = __gconv_open (&conv_spec, &cd, 0);
  41
  42   __gconv_destroy_spec (&conv_spec);
  43
  44   if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
  45     {
  46       /* We must set the error number according to the specs.  */
  47       if (res == __GCONV_NOCONV || res == __GCONV_NODB)
  48         __set_errno (EINVAL);
  49
  50       cd = (iconv_t) -1;
  51     }
  52
  53   return (iconv_t) cd;
  54 }