.BR make ,
you must write a file called the
.I makefile
-that describes the relationships among files in your program, and the states
-the commands for updating each file. In a program, typically the executable
-file is updated from object files, which are in turn made by compiling source
+that describes the relationships among files in your program, and provides
+commands for updating each file. In a program, typically the executable file
+is updated from object files, which are in turn made by compiling source
files.
.LP
Once a suitable makefile exists, each time you change some source files,