ref: b9c1eaa2de919a6c1a323826eba1a9e63e3d149c
dir: /sys/src/libc/port/utfrune.c/
#include <u.h>
#include <libc.h>
char*
utfrune(char *s, long c)
{
long c1;
Rune r;
int n;
if(c < Runesync) /* not part of utf sequence */
return strchr(s, c);
for(;;) {
c1 = *(uchar*)s;
if(c1 < Runeself) { /* one byte rune */
if(c1 == 0)
return 0;
if(c1 == c)
return s;
s++;
continue;
}
n = chartorune(&r, s);
if(r == c)
return s;
s += n;
}
}