about the makefile

can anyone well explain how to create a makefile? especially those commands in the makefile?

BTW, what is CFLAG?

See this - How to write a Makefile

Another useful link - Java Makefile

CFLAGS are usually the compiler options that are passed to the C/C++ compiler.

nothing to do with make file it is easy
and copy one sample make file from example programming.

change the path accrding to ur file systems.

where as CFLAG is C FLAGS has to be set those are macros
defined in the pre compiler those will be intialized.