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
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <alloca.h>
  20 #include <errno.h>
  21 #include <iconv.h>
  22 #include <stdbool.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   __gconv_t cd;
  34   struct gconv_spec conv_spec;
  35
  36   if (__gconv_create_spec (&conv_spec, fromcode, tocode) == NULL)
  37     return (iconv_t) -1;
  38
  39   int res = __gconv_open (&conv_spec, &cd, 0);
  40
  41   __gconv_destroy_spec (&conv_spec);
  42
  43   if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
  44     {
  45       /* We must set the error number according to the specs.  */
  46       if (res == __GCONV_NOCONV || res == __GCONV_NODB)
  47         __set_errno (EINVAL);
  48
  49       cd = (iconv_t) -1;
  50     }
  51
  52   return (iconv_t) cd;
  53 }