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/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2011 AT&T Intellectual Property *
* and is licensed under the *
* Eclipse Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.eclipse.org/org/documents/epl-v10.html *
* (with md5 checksum b35adb5213ca9657e911e9befb180842) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* convert wide character to utf8 in s
* s must have room for at least 6 bytes
* number of chars in placed in s returned
* thanks Tom Duff
*/
#include <ast.h>
typedef struct Utf8_s
{
uint32_t range;
unsigned short prefix;
unsigned short shift;
} Utf8_t;
static const Utf8_t ops[] =
{
{ 0x00000080, 0x00, 0 },
{ 0x00000800, 0xc0, 6 },
{ 0x00010000, 0xe0, 12 },
{ 0x00200000, 0xf0, 18 },
{ 0x04000000, 0xf8, 24 },
{ 0x80000000, 0xfc, 30 }
};
int
wc2utf8(register char* s, register uint32_t w)
{
register int i;
char* b;
for (i = 0; i < elementsof(ops); i++)
if (w < ops[i].range)
{
b = s;
*s++ = ops[i].prefix | (w >> ops[i].shift);
switch (ops[i].shift)
{
case 30: *s++ = 0x80 | ((w >> 24) & 0x3f);
case 24: *s++ = 0x80 | ((w >> 18) & 0x3f);
case 18: *s++ = 0x80 | ((w >> 12) & 0x3f);
case 12: *s++ = 0x80 | ((w >> 6) & 0x3f);
case 6: *s++ = 0x80 | (w & 0x3f);
}
return s - b;
}
return 0;
}
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