The Java socket interface and the C/UNIX socket interface provide basically the same set of features, but the C/UNIX interface requires the programmer to do more things explicitly, whereas the Java interface hides many of these details.
Compare the code on pages 45-48 of the text with the KnockKnock code from the Java tutorial. Give three examples of things that have to be done explicitly in C/UNIX that do not appear in the Java code.