char *stringcopy(const char *s, int len);
char *addr2string(struct sockaddr *addr);
-int addr_equal(struct sockaddr *a, struct sockaddr *b);
struct sockaddr *addr_copy(struct sockaddr *in);
-uint16_t port_get(struct sockaddr *sa);
void port_set(struct sockaddr *sa, uint16_t port);
void printfchars(char *prefixfmt, char *prefix, char *charfmt, char *chars, int len);
-int connectport(int type, char *host, char *port);
int bindtoaddr(struct addrinfo *addrinfo, int family, int reuse, int v6only);
int connecttcp(struct addrinfo *addrinfo, struct addrinfo *src);