ref: e9b2b1562c1295c164d3d416414cef0af257a7c2
dir: /sys/src/libc/port/runestrchr.c/
#include <u.h>
#include <libc.h>
Rune*
runestrchr(Rune *s, Rune c)
{
Rune r;
if(c == 0)
while(*s++)
;
else
while((r = *s++) != c)
if(r == 0)
return 0;
return s-1;
}