4.4 Suffix rules
To simplify a `Makefile', there is a special kind of rule syntax
known as a suffix rule. This is a wildcard pattern that can
match targets. Our first `Makefile' used some. Here is one:
Unless a more specific rule matches the target being sought, this rule
will match any target that ends in `.o'. These files are said to
always be dependent on `.c'. With some background material now
presented, let's take a look at these tools in use.