http://markuskimius.wikidot.com/programming:tut:autotools:3
1.     Write your program, keeping portability in mind. Create “Makefile.in”.
2.     Run “autoscan”.
3.     Rename “configure.scan” to “configure.ac”
4.     Run “autoheader”.
5.     Run “autoconf”.
6.     “./configure”.
7.     Check “config.h”. If necessary, modify source and repeat from step #2.
8.     And lastly, compile!