A program can communicate with other computers, or with other processes running in the same computer, via sockets. The sockets are identified by file descriptors.
= (string host, int port) int ¶This procedure creates a stream socket and connects it to the given
host using port port. The established communication is
full-duplex, and allows sending and receiving data using transput
until it gets closed. On success this procedure yields a file
descriptor. On error this procedure yields -1 and errno is set
appropriately.