Using a makefile

[TreeFinger]

I am reading a book on programming in C.

It is getting into working on larger projects and showed how to make a simple little makefile.

I have never used a makefile before and the book is a little old.. it is from 1999 so I want to make sure I am doing everything right.

File: makefile.gcc

#-------------------------------------------------#
#	Makefile for Unix systems					  #
#	Using a GNU C compiler						  #
#-------------------------------------------------#
CC=gcc
CFLAGS=-g -D__USE_FIXED_PROTOTYPES__ -ansi
#
# Compiler flags:
#		-g	-- Enable debugging
#		-Wall	-- Turn on all warnings 
#		-D__USE_FIXED_PROTOTYPES__
#			-- Force the compiler to use the correct headers
#		-ansi	-- Don't use GNU extensions. Stick to ANSI C.

7-1: 7-1.c
	$(CC) $(CFLAGS) -o output 7-1.c

clean:
	rm -f output

In terminal I type:

$ make -f makefile.gcc
gcc -g -D__USE_FIXED_PROTOTYPES__ -ansi -o output 7-1.c
$

Is this makefile workable? I compiled the program before making the makefile with gcc so I don't think makefile will do it again.

[Mr. C.]

It is usable, but not quite correct. You should also change the -o output to -o 7-1, and of course update your clean rule to use the correct name as well.

You'll want to make some changes when you have more than one source file.

You can test that it works:

touch 7-1.c
make -f makefile.gcc

or even

rm 7-1
make -f makefile.gcc

Do yourself a favor - rename makefile.gcc to Makefile, and then all you have to do is type:

make

MrC

[Wim Sturkenboom]

I have posted a universal makefile on http://www.linuxquestions.org/questi...d.php?t=380437 (post #4).
Only thing it does not do is descend into subdirectories (which would be very usefull for bigger projects).

[TreeFinger]

Mr. C.

Thanks for the tips. Everything is working great now, typing 'make' is a lot easier

Is there anyway I could make my makefile automatically execute the new executable file after compiling if there are no errors?

[Mr. C.]

Sure,

Change:

7-1: 7-1.c
	$(CC) $(CFLAGS) -o output 7-1.c

to

7-1: 7-1.c
	$(CC) $(CFLAGS) -o output 7-1.c
        ./7-1

Your 7.1 command will run only after the previous CC command completes successfully.

MrC