Makefile Exercise

Download the tarfile inclass_exercise.tar,
  wget http://web.engr.oregonstate.edu/~traylor/ece473/inclass_exercises/makefiles/makefiles2/inclass_exercise.tar
and untar it into a temporary working area.
  tar xvf inclass_exercise.tar

All the component files that constitute the executable "edit" will be in 
the directory as well as the makefile. In the directions that follow,
the default c compiler in Linux, "cc", is used instead of the gnu 
c compiler for the AVR "avr-gcc". The difference is of no consequence.

Using the given makefile..., 

1. List the series of instructions that would be executed and output to 
   the screen by make if the makefile had never been run to create the 
   executable "edit". On each line tell what is happening. If you are 
   not sure what is being done, type "make clean", followed by "make". 
   The commands executed by make will be transcripted to the shell.

2. After successfully doing a "make", i.e., all the files are up to date,
   suppose that command.h was edited. If make is executed again, what
   commands would be executed?  

   You can check your answer easily. First, check the timestamp on all 
   your .c or .h files using "ls" with "time-style" modified to return 
   the time stamp down to the second or fraction of a second.
     Linux users    -> ls -l --full-time 
     Mac (BSD UNIX) -> ls -l -T
   Note that all the *.o files have a newer timestamp than the .c or 
   .h files.  This tells make that the .o files are up to date. Also
   note all the *.o files were created in the same second.

   Now type "touch command.h" to modify the time stamp on command.h.
   Execute the "ls" command again and note the different timestamp on
   command.h. Since command.h is newer than the files that depend on
   it (files.o, command.o, kbd.o), those files must be recreated by
   compiling the corresponding *.c files.

   So when make is run again, we should see the files that depended
   on command.h recompiled, followed by the link.

3. Now suppose that all the files were up to date and then utils.c was 
   touched and make executed. What commands would be executed by make?

4. Replace the hard tab in the second line of the rule:
   edit : $(OBJECTS)
         cc -o edit $(OBJECTS)
   with 8 spaces instead. Then run make. What does make report?

-------- The given Makefile is shown below ----------------------------

OBJECTS = main.o kbd.o command.o display.o \
          insert.o search.o files.o utils.o
     
edit : $(OBJECTS)
	cc -o edit $(OBJECTS)
     
main.o    : defs.h
files.o   : defs.h buffer.h command.h
command.o : defs.h command.h
kbd.o     : defs.h command.h
display.o : defs.h buffer.h
insert.o  : defs.h buffer.h
search.o  : defs.h buffer.h
utils.o   : defs.h
clean     :
	rm edit $(OBJECTS)