Exploring a Slackware SlackBuild
Published: 2022-01-14 | Last Updated: 2022-01-14 | ~16 Minute Read
Table of Contents
- Introduction
- Prerequisites
- Downloading the source code
- Checking for a toolchain
- Checking for pkgtools
- Package naming
- Exploring the pkgtools sources
- Building the program and package
- Conclusion
Introduction
We’ve previously discussed general package management and Slackware package management so I thought I’d build on that by going over the anatomy of a Slackware SlackBuild script that you can use to install software on your system. SlackBuilds are usually associated with the third party slackbuilds.org repository, however they clarify that this was not something they originated.
Prerequisites
You should have a full Slackware installation but the general minimum requirements are:
- The sources for your application
- A build toolchain installed on your system
- The native Slackware pkgtools.
This should be enough to create most packages from a SlackBuild, and more than enough for the package we will inspect today, Slackware’s own pkgtools!
Downloading the source code
We can get the pkgtools sources from an available Slackware mirror, in my case I’ll use the Slackware UK mirror:
Create the directory where we will be working:
bash-5.1$ mkdir build-package
Change directory into the newly created working directory:
bash-5.1$ cd build-package
Download the sources from the Slackware mirror via wget:
bash-5.1$ wget --recursive --no-host-directories --cut-dirs=4 --execute robots=off --no-parent --reject "index.html" https://slackware.uk/slackware/slackware64-14.2/source/a/pkgtools/
A brief explanation of the wget options used:
--recursive- Turn on recursive retrieving. This will download content in subfolders ofpkgtools--no-host-directories- Disable generation of host-prefixed directories i.e noslackware.ukfolder created--cut-dirs=4- Ignore number directory components. This will allow us to create only thepkgtoolsdirectory instead of the defaultslackware/slackware64-14.2/source/a/pkgtools/structure--execute robots=off- Execute command as if it were a part of.wgetrc. This avoids downloading therobots.txtfile--no-parent- Do not ever ascend to the parent directory when retrieving recursively. This will make sure we only download files under thepkgtoolspath--reject "index.html"- Specify comma-separated lists of file name suffixes or patterns to accept or reject. This avoids downloading theindex.htmlfile
Let’s confirm that we have downloaded the sources into our build-package directory:
bash-5.1$ pwd
/tmp/build-package
bash-5.1$ ls
pkgtools
bash-5.1$ tree
.
└── pkgtools
├── manpages
│ ├── explodepkg.8
│ ├── installpkg.8
│ ├── makepkg.8
│ ├── pkgtool.8
│ ├── removepkg.8
│ └── upgradepkg.8
├── manpages-l10n.tar.xz
├── obsolete-scripts
│ ├── README
│ └── setup.90.modem-device
├── pkgtools.SlackBuild
├── scripts
│ ├── explodepkg
│ ├── installpkg
│ ├── makebootdisk
│ ├── makepkg
│ ├── pkgtool
│ ├── removepkg
│ ├── setup.70.install-kernel
│ ├── setup.80.make-bootdisk
│ ├── setup.htmlview
│ ├── setup.services
│ └── upgradepkg
└── slack-desc
4 directories, 22 files
bash-5.1$
Great, we have what we’ll need.
Checking for a toolchain
This is a very in depth subject that warrants its own post, hence I chose a package that will not require compiling and I will do a deep dive into the topic on a later post. The software toolchain is necessary to install most software that would be needed by a Slackware system user and so it is included as part of the “Full” installation.
The detailed list of packages that Slackware includes for building other software is in the /d series of packages and can be found on any mirror or installation media, for brevity I will only showcase how to check for gcc and make on your local system:
Checking for gcc:
Using traditional commands as any user:
bash-5.1$ ls /var/log/packages | grep -i "gcc"
gcc-10.2.0-x86_64-2
gcc-brig-10.2.0-x86_64-2
gcc-g++-10.2.0-x86_64-2
gcc-gdc-10.2.0-x86_64-2
gcc-gfortran-10.2.0-x86_64-2
gcc-gnat-10.2.0-x86_64-2
gcc-go-10.2.0-x86_64-2
gcc-objc-10.2.0-x86_64-2
gccmakedep-1.0.3-noarch-2
Using slackpkg as root:
root@host:~# slackpkg search gcc
Looking for gcc in package list. Please wait... DONE
The list below shows all packages with name matching "gcc".
[ Status ] [ Repository ] [ Package ]
upgrade slackware64 gcc-10.2.0-x86_64-2 --> gcc-11.2.0-x86_64-2
upgrade slackware64 gcc-brig-10.2.0-x86_64-2 --> gcc-brig-11.2.0-x86_64-2
upgrade slackware64 gcc-g++-10.2.0-x86_64-2 --> gcc-g++-11.2.0-x86_64-2
upgrade slackware64 gcc-gdc-10.2.0-x86_64-2 --> gcc-gdc-11.2.0-x86_64-2
upgrade slackware64 gcc-gfortran-10.2.0-x86_64-2 --> gcc-gfortran-11.2.0-x86_64-2
upgrade slackware64 gcc-gnat-10.2.0-x86_64-2 --> gcc-gnat-11.2.0-x86_64-2
upgrade slackware64 gcc-go-10.2.0-x86_64-2 --> gcc-go-11.2.0-x86_64-2
upgrade slackware64 gcc-objc-10.2.0-x86_64-2 --> gcc-objc-11.2.0-x86_64-2
upgrade slackware64 gccmakedep-1.0.3-noarch-2 --> gccmakedep-1.0.3-noarch-4
You can search specific files using "slackpkg file-search file".
gcc is installed along with several other packages that add functionality to compile different languages.
Note: Here we can see that I have some pending updates on my system, but I will wait until Slackware 15 is officially released to do a full installation :)
Checking for make:
Using traditional commands as any user:
bash-5.1$ ls /var/log/packages | grep -i "make"
automake-1.16.2-noarch-1
cmake-3.19.2-x86_64-1
gccmakedep-1.0.3-noarch-2
imake-1.0.8-x86_64-1
make-4.2.1-x86_64-7
makedepend-1.0.6-x86_64-1
pmake-1.111-x86_64-5
windowmaker-0.95.9-x86_64-1
Using slackpkg as root:
root@host:~# slackpkg search make
Looking for make in package list. Please wait... DONE
The list below shows all packages with name matching "make".
[ Status ] [ Repository ] [ Package ]
uninstalled slackware64 extra-cmake-modules-5.90.0-x86_64-1
upgrade slackware64 automake-1.16.2-noarch-1 --> automake-1.16.2-noarch-4
upgrade slackware64 cmake-3.19.2-x86_64-1 --> cmake-3.21.4-x86_64-1
upgrade slackware64 gccmakedep-1.0.3-noarch-2 --> gccmakedep-1.0.3-noarch-4
upgrade slackware64 imake-1.0.8-x86_64-1 --> imake-1.0.8-x86_64-3
upgrade slackware64 make-4.2.1-x86_64-7 --> make-4.3-x86_64-3
upgrade slackware64 makedepend-1.0.6-x86_64-1 --> makedepend-1.0.6-x86_64-3
upgrade slackware64 pmake-1.111-x86_64-5 --> pmake-1.111-x86_64-7
upgrade slackware64 windowmaker-0.95.9-x86_64-1 --> windowmaker-0.95.9-x86_64-3
You can search specific files using "slackpkg file-search file".
make is also installed on the system along with additional make packages for compatibility.
In case these packages are missing in your system you can install them easily with slackpkg:
# slackpkg install d
This will indicate to slackpkg that you want to install the d package series. All packages inside that series will then be fetched and installed from the mirror you have specified in /etc/slackpkg/mirrors.
Slackware’s pkgtools is created using bash scripts so we won’t actually compile anything in this case (Again I will create a separate post where we go more in depth on compiling packages), but in most other cases you will need this software.
Checking for pkgtools
In the same way that we checked for gcc and make we will check the system for pkgtools:
Using traditional commands as any user:
bash-5.1$ ls /var/log/packages | grep -i pkgtools
pkgtools-15.0-noarch-34
Using slackpkg as root:
root@host:~# slackpkg search pkgtools
Looking for pkgtools in package list. Please wait... DONE
The list below shows all packages with name matching "pkgtools".
[ Status ] [ Repository ] [ Package ]
upgrade slackware64 pkgtools-15.0-noarch-34 --> pkgtools-15.0-noarch-42
You can search specific files using "slackpkg file-search file".
Now that we confirmed that all of our prerequisites are met, we can move to taking a look at the package name structure.
Package naming
A very important aspect of packages in Slackware are the package names. The name of every package contains details about that package, from the documentation:
- the program name
- the program version
- the architecture of the package
- the build number
These different pieces of information are obtained from the package name and the following SlackBuild section:
# *** UPDATE THESE WITH EACH BUILD:
VERSION=14.2
ARCH=${ARCH:-noarch}
BUILD=10
Let’s analyze a few package names:
brave-browser-1.21.73-x86_64-1_SBo.tgz
| ========= | | === | | == | | = | |=|
| | | | |
program name version | build |
| number |
| |
architecture |
|
compression
type
filezilla-3.51.0-x86_64-1_SBo.tgz
| ===== | | == | | == | | = | |=|
| | | | |
program version | build |
name | number |
| |
architecture |
|
compression
type
pkgtools-14.2-noarch-10.txz
| ==== | |==| | == | || |=|
| | | | |
program version | build |
name | number|
| |
architecture |
|
compression
type
This naming convention makes it simple to look at the packages and immediately know important information for system maintenance.
Exploring the pkgtools sources
Now we will analyze the downloaded files to better understand what they provide for us.
There are three main components to every package:
- Program source
slack-desc&program.infoprogram.SlackBuildscript
Additionally to these three components we can sometimes find other files:
doinst.sh- A script describing post-install actions which is later moved to/var/log/scripts, more information here.rc.package- Startup scripts that the package may need, later moved to/etc/rc.d/.
Now we can take a closer look at the three main sections:
Program source
Again the source code for pkgtools are a set of bash scripts that we can easily check by using a text editor or command line utilities:
bash-5.1$ cd pkgtools/scripts/
bash-5.1$ pwd
/tmp/build-package/pkgtools/scripts
bash-5.1$ head installpkg
#!/bin/sh
# Copyright 1994, 1998, 2000 Patrick Volkerding, Concord, CA, USA
# Copyright 2001, 2003 Slackware Linux, Inc., Concord, CA, USA
# Copyright 2007, 2009, 2011 Patrick Volkerding, Sebeka, MN, USA
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
bash-5.1$
slack-desc & program.info
Here we can see that pkgtools does not have a pkgtools.info (program.info) file, this seems to be because the source is provided by Patrick Volkerding himself and not a different upstream.
We do have a slack-desc file with the recommended standard formatting ( see here for more details on slack-desc files):
bash-5.1$ cat slack-desc
# HOW TO EDIT THIS FILE:
# The "handy ruler" below makes it easier to edit a package description. Line
# up the first '|' above the ':' following the base package name, and the '|' on
# the right side marks the last column you can put a character in. You must make
# exactly 11 lines for the formatting to be correct. It's also customary to
# leave one space after the ':'.
| -----handy-ruler------------------------------------------------------ |
pkgtools: pkgtools (The Slackware package maintenance system)
pkgtools:
pkgtools: This package contains utilities for handling Slackware packages.
pkgtools: Included are the command line utilities 'installpkg', 'removepkg',
pkgtools: 'makepkg', 'explodepkg', and 'upgradepkg' that install, remove,
pkgtools: build, examine, and upgrade software packages. Also included are
pkgtools: 'pkgtool', a menu based program for installing packages, removing
pkgtools: packages, or viewing the packages that are installed on the system,
pkgtools: documentation (man pages), and a few other system admin scripts.
pkgtools:
pkgtools:
Program SlackBuild
This file contains instructions for the compilation/build steps of the installation process. Depending on the framework/language the package you’re trying to install uses you will most likely have a different SlackBuild script. The community maintained slackbuilds.com project provides some very handy templates that can get you started if you decide to create a SlackBuild of your own. In case you do opt to create your own package SlackBuild, make sure to check the submission guidelines over at the slackbuilds project.
In our example, since there are no binary files, the SlackBuild script only moves files into their appropriate locations, Let’s break down the script section by section and go over what is being automated.
The first section contains the SlackBuild license:
bash-5.1$ cat pkgtools.SlackBuild
#!/bin/sh
# Copyright 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Patrick J. Volkerding, Sebeka, MN, USA
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
# WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
# EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
# OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
# OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
# ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This section defines base variables that the SlackBuild will use:
# Set initial variables:
CWD=`pwd`
if [ "$TMP" = "" ]; then
TMP=/tmp
fi
PKG=$TMP/package-pkgtools
We took a look at these variables earlier, they are used to properly name the resulting package from the SlackBuild:
# *** UPDATE THESE WITH EACH BUILD:
VERSION=14.2
ARCH=${ARCH:-noarch}
BUILD=10
This section creates the $TMP path, /tmp by default, if not found and cleans up before starting work:
if [ ! -d $TMP ]; then
mkdir -p $TMP # location to build the source
fi
rm -rf $PKG
mkdir -p $PKG
We then compress and move the man pages that came bundled with the program source files into the appropriate location, compression optimizes final package sizes and the man command can decompress these on demand:
# Install Slackware script manpages:
( cd $CWD/manpages
mkdir -p $PKG/usr/man/man8
for page in explodepkg.8 installpkg.8 makepkg.8 upgradepkg.8 pkgtool.8 \
removepkg.8 ; do
cat $page | gzip -9c > $PKG/usr/man/man8/$page.gz
done
)
Additional internationalized man pages are then added as well:
# Install internationalized manpages from
# http://slint.fr/forSlackware/man_l10n/pkgtools/
( cd $PKG/usr/man
tar xf $CWD/manpages-l10n.tar.xz
for page in manpages-l10n/* ; do
manpage=$(basename $page)
mkdir -p ${manpage%%.*}/man8
mv $page ${manpage%%.*}/man8/${page#*.}.8
done
gzip -9 */man8/*.8
rmdir manpages-l10n
)
Now we move on to the actual utilities that come with pkgtools and begin placing them in their corresponding folders inside the $PKG variable, effectively /tmp/package-pkgtools at this point:
# Install Slackware scripts:
( cd $CWD/scripts
# Install the core Slackware package tools:
mkdir -p $PKG/sbin
# Don't include makebootdisk... it's useless since a kernel won't fit on a
# floppy disk, and nobody uses floppies any more anyway.
for file in explodepkg installpkg makepkg pkgtool removepkg upgradepkg ; do
cp -a $CWD/scripts/$file $PKG/sbin
done
chown root:root $PKG/sbin/*
chmod 755 $PKG/sbin/*
These sripts are also used during the initial system installation so they are placed accordingly:
# These scripts are used during the installation:
mkdir -p $PKG/var/log/setup/tmp
chmod 700 $PKG/var/log/setup/tmp
for file in setup.* ; do
cp -a $file $PKG/var/log/setup
done
chown root:root $PKG/var/log/setup/setup.*
chmod 755 $PKG/var/log/setup/setup.*
# Add a link for makebootstick:
( cd $PKG/sbin ; ln -sf ../var/log/setup/setup.80.make-bootdisk makebootstick )
)
The slack-desc file is now placed into the $PKG/install directory:
mkdir -p $PKG/install
cat $CWD/slack-desc > $PKG/install/slack-desc
Finally with all the files in place we call the makepkg command in order to create a package tarball from all the files we just prepared:
# Build the package:
cd $PKG
makepkg -l y -c n $TMP/pkgtools-$VERSION-$ARCH-$BUILD.txz
This seems to be a note for Patrick from himself to make sure he updates the package information on every build since this is not part of the slackbuilds provided templates and he’s the person that most likely builds this package most often.
echo
echo "HEY -- did you remember to update the version numbers in the setup scripts?"
echo
Building the program and package
Once we have confirmed that the SlackBuild contains all the commands to properly build the software we can run the pkgtools.SlackBuild script to get our final package:
root@host:/tmp/build-package/pkgtools# ./pkgtools.SlackBuild
Slackware package maker, version 3.14159265.
Searching for symbolic links:
sbin/makebootstick ../var/log/setup/setup.80.make-bootdisk
Making symbolic link creation script:
( cd sbin ; rm -rf makebootstick )
( cd sbin ; ln -sf ../var/log/setup/setup.80.make-bootdisk makebootstick )
It is recommended that you make these lines your new installation script.
Would you like to make this stuff the install script for this package
and remove the symbolic links ([y]es, [n]o)? y
Removing symbolic links:
removed './sbin/makebootstick'
Creating your new ./install/doinst.sh...
This next step is optional - you can set the directories in your package
to some sane permissions. If any of the directories in your package have
special permissions, then DO NOT reset them here!
Would you like to reset all directory permissions to 755 (drwxr-xr-x) and
directory ownerships to root.root ([y]es, [n]o)? n
Creating Slackware package: /tmp/pkgtools-14.2-noarch-10.txz
./
install/
install/doinst.sh
install/slack-desc
sbin/
sbin/explodepkg
sbin/installpkg
sbin/makepkg
sbin/pkgtool
sbin/removepkg
sbin/upgradepkg
usr/
usr/man/
usr/man/de/
usr/man/de/man8/
...
var/
var/log/
var/log/setup/
var/log/setup/setup.70.install-kernel
var/log/setup/setup.80.make-bootdisk
var/log/setup/setup.htmlview
var/log/setup/setup.services
var/log/setup/tmp/
Slackware package /tmp/pkgtools-14.2-noarch-10.txz created.
HEY -- did you remember to update the version numbers in the setup scripts?
Now we confirm that the package was created as the script mentions:
root@host:/tmp/build-package/pkgtools# ls /tmp/pkgtools-14.2-noarch-10.txz
/tmp/pkgtools-14.2-noarch-10.txz
It’s important to note that the SlackBuild scripts usually don’t install the package for you, they simply compile the software and create the package in an automated fashion.
Once confirmed you can install it by running the installpkg utility from pkgtools:
root@host:/tmp/build-package/pkgtools# installpkg /tmp/pkgtools-14.2-noarch-10.txz
It’s worth noting that installpkg will write the package files onto the filesystem following the same file hierarchy that was outlined in the SlackBuild script, so it’s important that this matches your system’s filesystem hierarchy. This is one of the reasons that SlackBuilds are the preferred method for installing packages on Slackware Linux, they greatly minimize room for error since they adhere to Slackware’s filesystem hierarchy.
Conclusion
That was a brief overview of what the contents of a Slackware package are and what they provide to a user, you can of course simply use the regular ./configure > make > make install process, however the additional structure around the Slackware way to create/install packages via SlackBuilds aids the user in ease of maintainability of their system.