C语言：关于socket的基础知识点

/**
 *      ---结构体---
 *
 *      #include <sys/socket.h>
 *      struct sockaddr {
 *              unsigned short sa_family;
 *              char sa_data[14];
 *      }
 *
 *      #include <netinet/in.h>
 *      struct sockaddr_in {
 *              short int sin_family;           //sa_family_t
 *              unsigned short sin_port;        //in_port_t
 *              struct in_addr sin_addr;
 *              unsigned char sin_zero[8];
 *      }
 *
 *      #include <netinet/in.h>
 *      sturct in_addr {
 *              uint32_t s_addr;
 *      }
 */

/**
 * --IP转换---
 *  ulong inet_addr(const char *ip);    //将一个点分十进制的ip转换成一个网络字节序的长整型数
 *  int inet_aton(const char *ip, struct in_addr *inp);         //将一个字符串ip转换成一个32位的网络字节序
 *  char *inet_ntoa(sturct in_addr in);
 */

/**
 * ---域名转换---
 *  #include <netdb.h>
 *  struct hostent{
 *              char *h_name;
 *              char **h_aliases;
 *              short h_addrtype;
 *              short h_length;
 *              char **h_addr_list;
 *  }
 *  #define h_addr h_addr_list[0]
 *      sturct hostent *h = gethostbyname(const char *hostname); //结果会存在resbuf里边
 *
 */

/**
 * ---字节序转换---
 *  #include <arpa/inet.h>
 *  uint32_t htonl(uint32_t hostlong)
 *  uint32_t ntohl(uint32_t hostlong)
 *      uint16_t htons(unit16_t hostshort)
 *      uint16_t ntohs(uint16_t hostshort)
 */

/**
 *
 */

/**
 * 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 connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen);
 * int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen);
 * int send(int sockfd, const void *buf, size_t len, int flags);
 * int recv(int sockfd, void *buf, size_t len, int flags);
 */