1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2012 AT&T Intellectual Property * 5 * and is licensed under the * 6 * Eclipse Public License, Version 1.0 * 7 * by AT&T Intellectual Property * 8 * * 9 * A copy of the License is available at * 10 * http://www.eclipse.org/org/documents/epl-v10.html * 11 * (with md5 checksum b35adb5213ca9657e911e9befb180842) * 12 * * 13 * Information and Software Systems Research * 14 * AT&T Research * 15 * Florham Park NJ * 16 * * 17 * Glenn Fowler <gsf@research.att.com> * 18 * David Korn <dgk@research.att.com> * 19 * Phong Vo <kpv@research.att.com> * 20 * * 21 ***********************************************************************/ 22 #pragma prototyped 23 /* 24 * Glenn Fowler 25 * AT&T Research 26 * 27 * convert wide character to utf8 in s 28 * s must have room for at least 6 bytes 29 * return value is the number of chars placed in s 30 * thanks Tom Duff 31 */ 32 33 #include <ast.h> 34 35 typedef struct Utf8_s 36 { 37 uint32_t range; 38 unsigned short prefix; 39 unsigned short shift; 40 } Utf8_t; 41 42 static const Utf8_t ops[] = 43 { 44 { 0x00000080, 0x00, 0 }, 45 { 0x00000800, 0xc0, 6 }, 46 { 0x00010000, 0xe0, 12 }, 47 { 0x00200000, 0xf0, 18 }, 48 { 0x04000000, 0xf8, 24 }, 49 { 0x80000000, 0xfc, 30 } 50 }; 51 52 int 53 wc2utf8(register char* s, register uint32_t w) 54 { 55 register int i; 56 char* b; 57 58 for (i = 0; i < elementsof(ops); i++) 59 if (w < ops[i].range) 60 { 61 b = s; 62 *s++ = ops[i].prefix | (w >> ops[i].shift); 63 switch (ops[i].shift) 64 { 65 case 30: *s++ = 0x80 | ((w >> 24) & 0x3f); 66 /* FALLTHROUGH */ 67 case 24: *s++ = 0x80 | ((w >> 18) & 0x3f); 68 /* FALLTHROUGH */ 69 case 18: *s++ = 0x80 | ((w >> 12) & 0x3f); 70 /* FALLTHROUGH */ 71 case 12: *s++ = 0x80 | ((w >> 6) & 0x3f); 72 /* FALLTHROUGH */ 73 case 6: *s++ = 0x80 | (w & 0x3f); 74 } 75 return s - b; 76 } 77 return 0; 78 } 79