ref: aa5e90543f33b596e7d2e09645488f3a14e5ff20
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 = (unsigned char*)ap; c &= 0xFF; while(n > 0) { if(*sp++ == c) return sp-1; n--; } return 0; }