... prints out the full response for the given URL, including the response code, headers, and entity-body. If the user only wants the response code, he can use the -r option. Similarly, the -H option ... $opt_d); } The call to Getopts( ) indicates that we're interested in the -h, -H, -r, and -d command-line options. When Getopts( ) finds these switches, it sets $opt_* (where * is the switch ... to the socket as you would any other file handle (e.g., print <FH>;). Finally, either the client or server uses the close( ) or shutdown( ) routine to end the connection. Figure 4- 1...