I have a program which is built of main.c utils.h and utils.c.
utils contains all the functions I've used. I wrote this makefile:

however when I write the command make the computer prints:
make: `a.out' is up to date.

can someone explain what is wrong with this makefile and how a working one should look like?

Maybe it's telling you that a.out is up to date. (In other words none of the other files has been changed since the last time a.out was created/modified.)

The whole idea is that the make program only does as much work as it needs to do. If target files have later timestamps than their dependencies, those rules are not executed.

Do the files main.o and utils.o and a.out exist in that directory?
What are the timestamps for utils.c, main.c, utils.o, main.o, a.out?
(Just do "ls -l" at the command line and look at the times listed for each file.)

Try pasting the following lines at the bottom of your Makefile:



Then enter the following on your command line:


Then


Experiment with touching one or both of the source files and/or deleting one or both of the .o files and/or deleting a.out. Try make after each thing that you try.

Regards,

Dave

thank you for your help.