Again, the previous method for examining the current rules is recommended. The inference of prerequisites can be controlled. Shell commands associated with the target define the rule for making a .o file from a .c file. Any target that has no slashes in it and starts with a dot is identi- fied as a rule and not a true target. If a target or dependency name contains parentheses, it is assumed to be an archive library, the string within parentheses referring to a member within the library.
Rules pertaining to archive libraries have the form .
XX .a where the XX is the suffix from which the archive member is to be made. An unfortunate by-product of the current implementation requires the XX to be different from the suffix of the archive member. The most common use of the archive interface follows. In fact, the .c.a rule listed above is built into make and is unnecessary in this example. The substi- tution mode translates the .o to .c.