Example:

ex1: ex1.c ex1.h
     gcc -Wall -Werror -o ex1 ex1.c

The UNIX command make

• looks for a file named Makefile in the current directory
• and executes the gcc command

  prompt$ make gcc -Wall -Werror -o ex1 ex1.c

• or does nothing if the dependencies haven't changed since the last make

  prompt$ make make: `ex1' is up to date.