simple make example

• You can use variable by assigning it, and use it with $(), it can be anything, you can even think of it as a macro.
• You can use $@ to replace the target. @ is a good name to represent the goal(target).
• $+ means all prerequisites with space separated when multiple is given.
• %.o:%.c shows the relationship based on extension name. Don't forget it uses % not *.

# 1
# Defining the compiler:
CC=gcc

# Defining the object files:
objects = main.o example.o

# 2
# The default rule - compiling our main program:
all:	sample
		echo all: make complete

# 3
sample: $(objects)
	# If we get here, all the dependencies are now built.
	# Link it:
	$(CC) -o $@ $+

# 4
# Tell make how to build .o files from .c files:
%.o:%.c
	$(CC) -c $+
	
# 5
#Now make sure that make rebuilds files if included headers change:
main.o: main.h defs.h
example.o: example.h defs.h

http://linuxdevcenter.com/pub/a/linux/2002/01/31/make_intro.html?page=2

phony target in make

When you execute make clean, you are using phony target. phony target is a target that doesn't have the dependencies, but only the actions.

# Naming our phony targets
.PHONY: clean install

# Removing the executable and the object files
clean: 
		rm sample main.o example.o
		echo clean: make complete

# Installing the final product
install:
		cp sample /usr/local
		echo install: make complete

• What is the purpose of .PHONY in a makefile?
• Phony Targets