git: 9front

ref: 8fe4837b17c53d79949bf753472067c9975c8614
dir: /sys/src/libc/port/utfrrune.c/

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#include <u.h>
#include <libc.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;
	}
}