721: Mainline

To set up a socket connection, the server must do the following:

• Create the server end of the socket connection, using socket.
• Identify the network address of the server and a port number, using bind.
• Listen for an attempt by a client to establish a connection, using listen.

Then, once the server is listening, the client can do the following:

• Create the client end of the socket connection, using socket.
• Attempt to establish a connection to the listening server, using connect.

Then, once the client has attempted to establish a connection to the listening server, the server can do the following:

• Accept the offered connection, using accept.

Finally, once the connection is accepted, both the server and client can do the following:

• Assign pointer variables to the values returned by calls to fdopen, an acronym for file descriptor open.

The pointer variables that are assigned to the values returned from calls to fdopen are like the file pointers assigned to the values returned from calls to fopen. You soon see, in the hardcopy version of this book, that a program can read and write to the socket using those pointer variables as arguments to fscanf and fprintf.