Any line which begins with a sharp sign # is ignored by the
makefile as a comment. Comment lines can be used to leave
instructions for whoever has to use your makefile (including
yourself). They are also useful for allowing someone to select
between alternative definitions of macros. For example, several lines
of the makefile have been commented out here:
# for home machine #BASEDIR = /home/ola/book/code # for cs machines #BASEDIR = /usr/project/courses/cps008/lib # for acpub machines BASEDIR = /afs/acpub.duke.edu/users8/ola/courses/lib
The idea is that you should un-comment exactly one definition for BASEDIR, depending on which computer system you're using. By keeping these alternatives in the file with all but one hidden, you make it easier on yourself to move your project from one network to another.