ref: 2d56837b2fabf6a7cc11f02b51f20a1e35128c57
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; }