1/* Copyright (C) 1996-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <dlfcn.h>
19#include <gconv.h>
20#include <stdio.h>
21#include <string.h>
22#include <wchar.h>
23#include <wcsmbsload.h>
24
25#include <sysdep.h>
26
27
28int
29wctob (wint_t c)
30{
31 unsigned char buf[MB_LEN_MAX];
32 struct __gconv_step_data data;
33 wchar_t inbuf[1];
34 wchar_t *inptr = inbuf;
35 size_t dummy;
36 int status;
37 const struct gconv_fcts *fcts;
38
39 if (c == WEOF)
40 return EOF;
41
42 /* We know that only ASCII compatible encodings are used for the
43 locale and that the wide character encoding is ISO 10646. */
44 if (c >= L'\0' && c <= L'\x7f')
45 return (int) c;
46
47 /* Tell where we want the result. */
48 data.__outbuf = buf;
49 data.__outbufend = buf + MB_LEN_MAX;
50 data.__invocation_counter = 0;
51 data.__internal_use = 1;
52 data.__flags = __GCONV_IS_LAST;
53 data.__statep = &data.__state;
54
55 /* Make sure we start in the initial state. */
56 memset (&data.__state, '\0', sizeof (mbstate_t));
57
58 /* Get the conversion functions. */
59 fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
60
61 /* Create the input string. */
62 inbuf[0] = c;
63
64 const unsigned char *argptr = (const unsigned char *) inptr;
65 __gconv_fct fct = fcts->tomb->__fct;
66#ifdef PTR_DEMANGLE
67 if (fcts->tomb->__shlib_handle != NULL)
68 PTR_DEMANGLE (fct);
69#endif
70 status = DL_CALL_FCT (fct,
71 (fcts->tomb, &data, &argptr,
72 argptr + sizeof (inbuf[0]), NULL, &dummy, 0, 1));
73
74 /* The conversion failed or the output is too long. */
75 if ((status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
76 && status != __GCONV_EMPTY_INPUT)
77 || data.__outbuf != (unsigned char *) (buf + 1))
78 return EOF;
79
80 return buf[0];
81}
82

source code of glibc/wcsmbs/wctob.c