In this section, we’ll create a minimalist configure.ac, re-name our Makefile to Makefile.am, generate a configure script, and use this configure script to produce a Makefile. The end result won’t do much more than our manually-created Makefile. It will, however, allow us to make use of the autoconf and automake infrastructure in future lessons. So let’s get started.

Return to our workplace

$ cd ~/src/greeting

Create a configure.ac file

$ cat > configure.ac
AC_INIT([greeting],[0.0.1])
AM_INIT_AUTOMAKE([1.9 tar-ustar])
AC_PATH_PROG(CSC, gmcs, no)
if test "x$CSC" = "x" ; then
  AC_MSG_ERROR([Can't find "gmcs" in your PATH])
fi
AC_CONFIG_FILES([
Makefile
])
AC_OUTPUT
^D

Re-name your Makefile

$ mv Makefile Makefile.am

Install autoconf & automake

$ sudo apt-get install autoconf automake

Create files required by automake

$ for i in NEWS README AUTHORS ChangeLog ; do touch $i ; done

Import required m4 macros

$ aclocal

Ask automake to install missing pieces

$ automake -a

Process configure.ac and Makefile.am

$ autoreconf

Create a Makefile using configure script

$ ./configure

Test the targets we created before

$ make
gmcs -out:Greeting.exe Greeting.cs NDesk.Options.cs
$ make clean
rm Greeting.exe
$ make Greeting.exe
gmcs -out:Greeting.exe Greeting.cs NDesk.Options.cs

Verify that our code still runs

$ ./Greeting.exe -n 1
Greetings, Mercury!
$ ./Greeting.exe -1
Greetings, World!
$ ./Greeting.exe ––number 3
Greetings, Earth!

Try some of the targets that automake generates

$ touch Makefile.in && make Makefile
 cd . && /bin/sh ./config.status Makefile 
config.status: creating Makefile
make: `Makefile' is up to date.
$ make distdir
...
$ ls greeting-0.0.1
AUTHORS  ChangeLog  Makefile.am  NEWS    aclocal.m4  configure.ac  missing
COPYING  INSTALL    Makefile.in  README  configure   install-sh
$ make dist
...
$ ls greeting-0.0.1.tar.gz 
greeting-0.0.1.tar.gz

Conclusion

We have now created a simple autotools framework to do what we were doing manually. I’ll be honest: this is still pretty manual. In future lessons we’ll make some tweaks to it which make use of the extensive features of the system.