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 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