Unix Networking: Server

int sockfd, new_fd;
struct addrinfo hints, *servinfo, *p;
struct sockaddr_storage their_addr;
socklen_t sin_size;
struct sigaction sa;
int yes=1;
char s[INET6_ADDRSTRLEN];
int rv;

/* fill out the address structure */
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_PASSIVE;

/* get the address information */
getaddrinfo(NULL, PORT, &hints, &servinfo);

/* open the socket */
sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);

/* allow the socket to be re-used */
setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));

/* bind the socket to the address */
bind(sockfd, p->ai_addr, p->ai_addrlen);

/* free up the address structure */
freeaddrinfo(servinfo);

/* start the socket listening */
listen(sockfd, BACKLOG);

/* accept the first connect */
new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size);

/* send the client some data */
send(new_fd, "Hello, world!", 13, 0);

/* finished with the client & server */
close(new_fd);
close(sockfd);