Listen() System Call

The listen() system call prepares a connection-oriented server to accept client connections.

int listen(int sockfd, struct <backlog>);

■	The first parameter is the socket descriptor from the socket() call, sockfd.
■	The second parameter specifies the number of requests that the system queues before it executes the accept() system call. Higher and lower values of <backlog> trade off high efficiency for low latency.

For example:

listen(sockfd, 5);