1 /*
2 * This code was written by Rich Felker in 2010; no copyright is claimed.
3 * This code is in the public domain. Attribution is appreciated but
4 * unnecessary.
5 */
6
7 #include <wchar.h>
8 #include <errno.h>
9
wcrtomb(char * restrict s,wchar_t wc,mbstate_t * restrict st)10 size_t wcrtomb(char *restrict s, wchar_t wc, mbstate_t *restrict st)
11 {
12 if (!s) return 1;
13 if ((unsigned)wc < 0x80) {
14 *s = wc;
15 return 1;
16 } else if ((unsigned)wc < 0x800) {
17 *s++ = 0xc0 | (wc>>6);
18 *s = 0x80 | (wc&0x3f);
19 return 2;
20 } else if ((unsigned)wc < 0xd800 || (unsigned)wc-0xe000 < 0x2000) {
21 *s++ = 0xe0 | (wc>>12);
22 *s++ = 0x80 | ((wc>>6)&0x3f);
23 *s = 0x80 | (wc&0x3f);
24 return 3;
25 } else if ((unsigned)wc-0x10000 < 0x100000) {
26 *s++ = 0xf0 | (wc>>18);
27 *s++ = 0x80 | ((wc>>12)&0x3f);
28 *s++ = 0x80 | ((wc>>6)&0x3f);
29 *s = 0x80 | (wc&0x3f);
30 return 4;
31 }
32 errno = EILSEQ;
33 return -1;
34 }
35