The make program gets its dependency "graph" from a text file called makefile or Makefile which resides in the same directory as the source files. Make checks the modification times of the files, and whenever a file becomes "newer" than something that depends on it, (in other words, modified) it runs the compiler accordingly.
For example, the previous page explained io.c was changed. If
you edit
io.c, it becomes "newer" than io.o, meaning that
make must run cc -c io.c to create a new io.o, then
run cc data.o main.o io.o -o project1 for project1.
Last updated on Wednesday, June 21, 1995 by
Ben
Y. Yoshino
Copyright © 1995 University of Hawai`i, College of Engineering,
Computer Facility
All rights reserved.