Automated Linux From Scratch (ALFS) is a project that allows building the LFS system automatically. It also allows building packages from the BLFS book, but that needs some manual intervention.
After having gone through the LFS and BLFS books more than 2 or 3 times, you will quickly appreciate the ability to automate the task of compiling the software you want for your systems.
The goal of ALFS is to automate the process of creating an LFS system. It seeks to follow the book as closely as possible by directly extracting instructions from the XML sources. This is the reason why it may also be used as a test of the current book instructions.
The official implementation of ALFS is called jhalfs. It was originally created by Jeremy Huntwork, then developed and maintained by Manuel Canales Esparcia, George Boudreau, Thomas Pegg, and Pierre Labastie. It has become a light-weight, practical method of automating an LFS build. It is a Bash shell script that makes use of Git and xsltproc to first download the XML sources of the Linux From Scratch book and then extract any necessary commands, placing them into executable shell scripts. If you do not already have the necessary source packages in place on your system, jhalfs can fetch them. Finally, jhalfs generates a Makefile which will control the execution of the shell scripts, allowing for recovery if the build should encounter an error. A framework to use package management has been added by Pierre Labastie.
Due to a lack of developers, jhalfs is maintained as a rolling release. It can be obtained by cloning the git repository:
git clone git://git.linuxfromscratch.org/jhalfs.git jhalfs
An extension of ALFS aimed at automating the building of packages in the BLFS book is now included in jhalfs. It still needs editing some scripts (about 1%), mainly when the book layout diverges from standard, but works rather well and most of the packages can be built automatically.
Before jhalfs, an implementation named nALFS was developed. A more ambitious project, named simply alfs was designed around 2004, but was never pushed to completion.
The first ALFS implementation was nALFS by Neven Has. nALFS was a small program written in C. It first parsed an XML profile that contained information concerning the LFS build process into a series of internal commands. It could then execute these at your discretion, thus automating the compilation of LFS.
There were many in-depth features that had been requested for ALFS implementations. Because of this, development had been slated for an entirely new build tool which would have been called alfs. Eventually, the ease of use of jhalfs ultimately pushed development of alfs to the bottom of the stack.