????type:??????????

????protocol??Э?????????????????0????????????family??type??????????

????#include<arpa/inet.h>
????int inet_pton(int family??const char *strptr??void *addrptr);//???????1????????????0?????????-1
????//?????p??????? n???????  ?????д?????д????ж??п????????????????????????????????
????//??char????????????????addrptr?????
????//???????????  inet_ntop???????????????????????????????????????????????????漰???????????????????????????
????//??????????????????????????errno????????EAFNOSUPPORT ????errno??????????????
????#include <sys/socket.h>
????int connect(int sockfd??const struct sockaddr* servaddr??socklen_t addrlen);//??connect????????????TCP????????????
????> 3???????????????????TCP????????????齻??
????> 4??IPv4??IPv6??????????
????> 5???Щ???????????
????> 6??????????