5. how it works
아래 순서로 진행된다.
aclocal : configure.ac --> aclocal.m4
autoheader : configure.ac + aclocal.m4 --> config.h.in
autoconf : configure.ac + aclocal.m4 --> configure
automake : configure.ac + aclocal.m4 + Makefile.am --> Makefile.in
configure : Makefile.in --> Makefile
