1 /*
2 Copyright (c) 1990 Regents of the University of California.
3 All rights reserved.
4 */
5 /*
6 FUNCTION
7 <<wctomb>>---minimal wide char to multibyte converter
8
9 INDEX
10 wctomb
11
12 SYNOPSIS
13 #include <stdlib.h>
14 int wctomb(char *<[s]>, wchar_t <[wchar]>);
15
16 DESCRIPTION
17 When _MB_CAPABLE is not defined, this is a minimal ANSI-conforming
18 implementation of <<wctomb>>. The
19 only ``wide characters'' recognized are single bytes,
20 and they are ``converted'' to themselves.
21
22 When _MB_CAPABLE is defined, this routine calls <<_wctomb_r>> to perform
23 the conversion, passing a state variable to allow state dependent
24 decoding. The result is based on the locale setting which may
25 be restricted to a defined set of locales.
26
27 Each call to <<wctomb>> modifies <<*<[s]>>> unless <[s]> is a null
28 pointer or _MB_CAPABLE is defined and <[wchar]> is invalid.
29
30 RETURNS
31 This implementation of <<wctomb>> returns <<0>> if
32 <[s]> is <<NULL>>; it returns <<-1>> if _MB_CAPABLE is enabled
33 and the wchar is not a valid multi-byte character, it returns <<1>>
34 if _MB_CAPABLE is not defined or the wchar is in reality a single
35 byte character, otherwise it returns the number of bytes in the
36 multi-byte character.
37
38 PORTABILITY
39 <<wctomb>> is required in the ANSI C standard. However, the precise
40 effects vary with the locale.
41
42 <<wctomb>> requires no supporting OS subroutines.
43 */
44
45 #include <stdlib.h>
46 #include <errno.h>
47 #include "local.h"
48
49 int
wctomb(char * s,wchar_t wchar)50 wctomb (char *s,
51 wchar_t wchar)
52 {
53 #ifdef _MB_CAPABLE
54 static NEWLIB_THREAD_LOCAL mbstate_t _wctomb_state;
55
56 return __WCTOMB (s, wchar, &_wctomb_state);
57 #else /* not _MB_CAPABLE */
58 if (s == NULL)
59 return 0;
60
61 /* Verify that wchar is a valid single-byte character. */
62 if ((size_t)wchar >= 0x100) {
63 errno = EILSEQ;
64 return -1;
65 }
66
67 *s = (char) wchar;
68 return 1;
69 #endif /* not _MB_CAPABLE */
70 }
71
