ref: 2a03ed80e4fc52c327e47e1749c97b4e2c1aa1d8
dir: /sys/src/ape/lib/ap/gen/memchr.c/
#include <string.h>
void*
memchr(const void *ap, int c, size_t n)
{
unsigned char *sp;
sp = ap;
c &= 0xFF;
while(n > 0) {
if(*sp++ == c)
return sp-1;
n--;
}
return 0;
}