Summarize of network protocol in c

<netinet/in.h>  Internet Addr

in_port_t: uint16_t, 16 bits for ports

socket

<sys/socket.h>

 * create new socket

int socket (int namespace, int style, int protocol)

style: SOCK_STREAM or SOCK_DGRAM

 * bind a namespace to a socket

int bind(int sockfd, const struct sockaddr *addr,
         socklen_t addrlen);
struct sockaddr {
    sa_family_t sa_family;
    char        sa_data[14];
}

 * connect a socket

after a socket is created (maybe on another machine), use this to connect it

 int connect (int socket, struct sockaddr *addr, socklen_t length)

* send message through socket

send(int sockfd, const void *buf, size_t len, int flags);
write (socket, command, cmdlen)