ref: 90143609212ed4500409a64d26f6b12d097b13ed
dir: /sys/src/ape/lib/utf/utfrrune.c/
/*
* The authors of this software are Rob Pike and Ken Thompson.
* Copyright (c) 2002 by Lucent Technologies.
* Permission to use, copy, modify, and distribute this software for any
* purpose without fee is hereby granted, provided that this entire notice
* is included in all copies of any software which is or includes a copy
* or modification of this software and in all copies of the supporting
* documentation for such software.
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
*/
#include <stdarg.h>
#include <string.h>
#include "utf.h"
#include "utfdef.h"
char*
utfrrune(char *s, long c)
{
long c1;
Rune r;
char *s1;
if(c < Runesync) /* not part of utf sequence */
return strrchr(s, c);
s1 = 0;
for(;;) {
c1 = *(uchar*)s;
if(c1 < Runeself) { /* one byte rune */
if(c1 == 0)
return s1;
if(c1 == c)
s1 = s;
s++;
continue;
}
c1 = chartorune(&r, s);
if(r == c)
s1 = s;
s += c1;
}
}