1.代码编写问题
int socket(int domain, int type, int protocol);
int bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen);
int listen(int sockfd, int backlog);
int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen);
int connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen);
size_t write(int fd,const void *buf,size_t nbytes);
size_t read(int fd,void *buf,size_t nbyte);