#+TITLE: Carbs Linux User Manual
#+AUTHOR: Cem Keylan
#+TEXINFO_FILENAME: carbslinux.info
#+TEXINFO_DIR_CATEGORY: System Administration
#+TEXINFO_DIR_TITLE: Carbs Linux: (carbslinux)
#+TEXINFO_DIR_DESC: Carbs Linux User Manual
#+MACRO: contid [@@texinfo:@anchor{$1}@@$1]
#+MACRO: sectid $2 [@@texinfo:@anchor{$1}@@$1]

This is the full documentation of [[https://carbslinux.org][Carbs Linux]], from the details of the
distribution, installation, to the package manager. It is not yet complete.

* Table of Contents                                       :toc_3_gh:noexport:
- [[#copying][Copying]]
- [[#installation][Installation]]
  - [[#preparing-environment][Preparing Environment]]
    - [[#download][Download]]
    - [[#signature-verification][Signature verification]]
    - [[#extracting-the-tarball][Extracting the tarball]]
    - [[#obtain-the-chroot-helper][Obtain the chroot helper]]
  - [[#chroot][Chroot]]
    - [[#setting-up-repositories][Setting up repositories]]
    - [[#updating-packages][Updating packages]]
    - [[#installing-packages][Installing packages]]
    - [[#essential-software][Essential Software]]
    - [[#obtaining-the-documentation][Obtaining the documentation]]
  - [[#system-configuration][System Configuration]]
    - [[#configuring-hostname][Configuring hostname]]
    - [[#hosts-file][Hosts file]]
  - [[#kernel][Kernel]]
    - [[#obtaining-the-kernel-sources][Obtaining the kernel sources]]
    - [[#kernel-dependencies][Kernel dependencies]]
    - [[#building-the-kernel][Building the kernel]]
  - [[#making-your-system-bootable][Making your system bootable]]
    - [[#bootloader][Bootloader]]
    - [[#init-scripts][Init scripts]]
    - [[#fstab][Fstab]]
  - [[#post-installation][Post-installation]]
    - [[#kiss-repositories][KISS repositories]]
- [[#package-manager][Package Manager]]
  - [[#usage][Usage]]
    - [[#cpt-alternatives][=cpt-alternatives=]]
    - [[#cpt-build][=cpt-build=]]
    - [[#cpt-checksum][=cpt-checksum=]]
    - [[#cpt-download][=cpt-download=]]
    - [[#cpt-install][=cpt-install=]]
    - [[#cpt-list][=cpt-list=]]
    - [[#cpt-remove][=cpt-remove=]]
    - [[#cpt-search][=cpt-search=]]
    - [[#cpt-update][=cpt-update=]]
    - [[#global-flags][Global Flags]]
  - [[#environment-variables][Environment Variables]]
    - [[#cpt_compress][=CPT_COMPRESS=]]
    - [[#cpt_force][=CPT_FORCE=]]
    - [[#cpt_pid][=CPT_PID=]]
  - [[#hooks][Hooks]]
    - [[#editing-the-build-file-during-pre-build][Editing the =build= file during pre-build]]
  - [[#packaging-system][Packaging System]]
    - [[#build][=build=]]
    - [[#sources][=sources=]]
    - [[#checksums][=checksums=]]
    - [[#version][=version=]]
    - [[#depends][=depends=]]
    - [[#post-install][=post-install=]]
    - [[#message][=message=]]
    - [[#test][=test=]]
  - [[#rsync-repositories][Rsync Repositories]]
    - [[#setting-up-an-rsync-repository][Setting up an Rsync repository]]
- [[#init-system][Init System]]
  - [[#configuring-init][Configuring Init]]
    - [[#kernel-command-line][Kernel Command Line]]
    - [[#etcinitrcconf-file][=/etc/init/rc.conf= file]]
    - [[#init-hooks][Init Hooks]]
  - [[#changing-init-program][Changing Init Program]]
    - [[#rebooting-after-changing-init][Rebooting after changing init]]
- [[#contribution-guidelines][Contribution Guidelines]]
  - [[#conventions][Conventions]]
    - [[#shell-conventions][Shell Conventions]]
    - [[#repository-conventions][Repository Conventions]]

* Copying
  :PROPERTIES:
  :COPYING:  t
  :END:

Copyright \copy 2020 Cem Keylan

#+BEGIN_QUOTE
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, with no Front-Cover Texts and no Back-Cover Texts.
A copy of the license is included in the section entitled "GNU Free
Documentation License."
#+END_QUOTE

* Installation
:PROPERTIES:
:DESCRIPTION: Installing Carbs Linux
:END:

These are the step-by-step instructions for installing Carbs Linux.

** Preparing Environment
:PROPERTIES:
:DESCRIPTION: Getting ready to chroot
:END:

To install Carbs Linux, you will need a Live Linux ISO. For that purpose, you
can obtain a Gentoo or Void Linux live image. You can follow their instructions
to boot and setup your network.

You will need the following programs in order to install Carbs Linux:

- tar
- wget
- xz
- some form of base utilities (coreutils, sbase, busybox, etc.)

Rest of these instructions will assume that you have set all of these up, and
will continue on that point.

*** Download
:PROPERTIES:
:DESCRIPTION: Download the root filesystem tarball
:END:

First, we need to download the rootfs tarball. You can do the following in order
to obtain the rootfs. If you are using an i686 machine, replace the =x86_64=
with =i686=. We are setting this in a URL variable so that we don't have to
write it every time.

#+BEGIN_EXAMPLE sh
  $ wget $URL/carbs-rootfs.tar.xz.sha256
  $ sha256sum -c carbs-rootfs.tar.xz.sha256
#+END_EXAMPLE

*** Signature verification
:PROPERTIES:
:DESCRIPTION: Verify the signature of the rootfs tarball
:END:

It is highly recommended to verify the signature of the tarball. You will need
GPG for this.

#+BEGIN_EXAMPLE
  $ wget $URL/carbs-rootfs.tar.xz.sig
  $ gpg --recv-keys FF484BDFEFCEF8FF
  $ gpg --verify carbs-rootfs.tar.xz.sig
#+END_EXAMPLE

*** Extracting the tarball
:PROPERTIES:
:DESCRIPTION: Extracting the root filesystem to the desired location
:END:

You will need to extract the tarball to your desired location. For partitioning,
you can follow [[https://wiki.archlinux.org/index.php/Partitioning][this guide]]. This will assume that you will be mounting your root
partition to =/mnt=.

#+BEGIN_EXAMPLE
  $ mount /dev/sdx1 /mnt
  $ tar xf carbs-rootfs.tar.xz -C /mnt
#+END_EXAMPLE

*** Obtain the chroot helper
:PROPERTIES:
:DESCRIPTION: Download the script to easily chroot into the new filesystem
:END:

You can obtain the =cpt-chroot= script in order to do a simple chroot into your
new root filesystem.

#+BEGIN_EXAMPLE
  $ wget https://dl.carbslinux.org/distfiles/cpt-chroot
  $ chmod a+x cpt-chroot
#+END_EXAMPLE

** Chroot
:PROPERTIES:
:DESCRIPTION: Going inside your new system
:END:

Chroot into Carbs Linux!

#+BEGIN_EXAMPLE
  $ ./cpt-chroot /mnt
#+END_EXAMPLE

*** Setting up repositories
:PROPERTIES:
:DESCRIPTION: Basic setup for obtaining repositories
:END:

Newest tarballs do not come with repositories, so you will need to manually
obtain them, and set your =CPT_PATH= environment variable. Carbs Linux
repositories can either be obtained by =git= or =rsync=. While rsync
repositories are overall faster and smaller, git offers the whole history of the
repository and a means to manipulate your repository as you like it. If you want
to obtain the git repository, you will need to install =git= itself.

The following guide will assume that you put the repositories into =~/repos/=
directory, but you can put the repositories into any directory you want. So go
ahead and create that directory:

#+BEGIN_EXAMPLE
  $ mkdir -p $HOME/repos
#+END_EXAMPLE

**** Obtaining from git

Carbs Linux git repositories can be found both from the main server and GitHub
(mirror). Here are both their repository links. You can clone any of them.

- git://git.carbslinux.org/repository
- https://github.com/carbslinux/repository

#+BEGIN_EXAMPLE
  $ git clone git://git.carbslinux.org/repository $HOME/repos/carbs
#+END_EXAMPLE

**** Obtaining from rsync

Carbs Linux rsync repositories live in rsync://carbslinux.org/repo. In
order to obtain it, run the following:

#+BEGIN_EXAMPLE
  $ rsync -avc rsync://carbslinux.org/repo $HOME/repos/carbs
#+END_EXAMPLE

**** Making the package manager use the repositories

In your shell's configuration file, or in your =~/.profile= file, add the
following lines:

#+BEGIN_EXAMPLE
  export CPT_PATH=''
  CPT_PATH=$CPT_PATH:$HOME/repos/carbs/core
  CPT_PATH=$CPT_PATH:$HOME/repos/carbs/extra
  CPT_PATH=$CPT_PATH:$HOME/repos/carbs/xorg
  CPT_PATH=$CPT_PATH:$HOME/repos/carbs/community
  export CPT_PATH
#+END_EXAMPLE

*** Updating packages
:PROPERTIES:
:DESCRIPTION: Update your system
:END:

It is good practice to make sure your system is up to date, especially before
building new packages. If there is an update for the package manager you will
need to update twice.

#+BEGIN_EXAMPLE
  $ cpt-update && cpt-update
#+END_EXAMPLE

*** Installing packages
:PROPERTIES:
:DESCRIPTION: Install new software on your system
:END:

Since you are operating on a really small base, you might need to build and
install new programs to extend the functionality of your system. In order to
build and install packages new packages in Carbs, you need to execute the
following. "Package" is not actually a package and is given as an example.

#+BEGIN_EXAMPLE
  $ cpt-build   package
  $ cpt-install package
#+END_EXAMPLE

*** Essential Software
:PROPERTIES:
:DESCRIPTION: Software you might want to include on your system
:END:

Here is a list of software that you might want to have on your system.

*BOOTLOADERS*

- efibootmgr
- grub

*FILESYSTEMS*

- e2fsprogs
- dosfstools
- ntfs-3g

*NETWORKING*

- dhcpcd
- wpa_supplicant

*TEXT EDITORS*

- nano
- vim
- neatvi
- emacs
- emacs-nox (terminal-only version of emacs)

*USER SHELLS*

- bash
- zsh
- oksh
- rc

*POSIX BASE UTILITIES*

- busybox
- sbase
- coreutils

*DOCUMENTATION*

- carbs-docs
- man-pages
- man-pages-posix

*** Obtaining the documentation
:PROPERTIES:
:DESCRIPTION: Install documentation for offline use (optional)
:END:

All the documentation for Carbs Linux can be found on a single info manual to be
viewed offline. You can obtain texinfo or the info (standalone) package in order
to view the documentation.

#+BEGIN_EXAMPLE
  Install the documentation.
  $ cpt b carbs-docs && cpt i carbs-docs

  Install either texinfo or the info package. We will be installing standalone info
  as it doesn't need perl.
  $ cpt b info && cpt i info

  You can then run info and navigate through the documentation.
  $ info carbslinux
#+END_EXAMPLE

** System Configuration
:PROPERTIES:
:DESCRIPTION: Customizing your system for personal use
:END:

After you have finished installing some extra packages, you can configure your
system to your liking.

*** Configuring hostname
:PROPERTIES:
:DESCRIPTION: Setting up system hostname (recommended)
:END:

You might want to add a hostname, especially in a networked environment. Your
hostname will default to 'carbslinux' unless you set this.

#+BEGIN_EXAMPLE
  $ echo your-hostname > /etc/hostname
#+END_EXAMPLE

*** Hosts file
:PROPERTIES:
:DESCRIPTION: Setting up hosts file for networking (optional)
:END:

You can edit your /etc/hosts file, which is the static lookup table for host
names. By default, there are two entries for localhost which are OKAY. You can
replace the 'localhost' part of these entries to your hostname.

#+BEGIN_EXAMPLE
  127.0.0.1  localhost.localdomain localhost
  ::1        localhost.localdomain localhost ip6-localhost
#+END_EXAMPLE

** Kernel
:PROPERTIES:
:DESCRIPTION: Compiling your own kernel
:END:

Kernel isn't managed under the main repositories, even though you could package
one for your personal use. Here is an [[https://github.com/cemkeylan/kiss-repository/tree/master/personal/linux][example kernel package]], which you will
need to reconfigure for your specific setup if you want to make use of it.

*** Obtaining the kernel sources
:PROPERTIES:
:DESCRIPTION: Downloading the Linux source code
:END:

You can visit the [[https://kernel.org]] website to choose a kernel that you want
to install. Though only the latest stable and longterm (LTS) versions are
supported.

#+BEGIN_EXAMPLE
  Download the kernel and extract it
  $ wget https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.9.1.tar.xz
  $ tar xf linux-5.9.1.tar.xz

  Change directory into the kernel sources
  $ cd linux-5.9.1
#+END_EXAMPLE

*** Kernel dependencies
:PROPERTIES:
:DESCRIPTION: Requirements for building the kernel
:END:

In order to compile the kernel you will need to install some dependencies. You
will need =libelf= to compile the kernel. If you want to configure using the
menu interface you will also need =ncurses=.

#+BEGIN_EXAMPLE
  The package manager asks to install if you are building more than one package,
  so no need to run 'cpt i ...'
  $ cpt b libelf ncurses
#+END_EXAMPLE

In the vanilla kernel sources, you need perl to compile the kernel, but it can
be easily patched out. You will need to apply the following patch. Patch was
written by [[https://github.com/E5ten][E5ten]]. You will need to obtain and apply the patch in the kernel
source directory.

#+BEGIN_EXAMPLE
  $ wget https://dl.carbslinux.org/distfiles/kernel-no-perl.patch
  $ patch -p1 < kernel-no-perl.patch
#+END_EXAMPLE

*** Building the kernel
:PROPERTIES:
:DESCRIPTION: Configure and compile the kernel
:END:

Next step is configuring and building the kernel. You can check Gentoo's
[[https://wiki.gentoo.org/wiki/Kernel/Configuration][kernel configuration guide]] to learn more about the matter. Overall, Gentoo Wiki
is a good place to learn about configuration according to your hardware. The
following will assume a monolithic kernel.

#+BEGIN_EXAMPLE
  $ make menuconfig
  $ make
  $ install -Dm755 $(make -s image_name) /boot/vmlinuz-linux
#+END_EXAMPLE

** Making your system bootable
:PROPERTIES:
:DESCRIPTION: Installing bootloader and boot scripts
:END:

In order to be able to boot your fresh system, wou will need an init-daemon,
init-scripts and a bootloader. The init daemon is already provided by busybox,
but you can optionally change it.

*** Bootloader
:PROPERTIES:
:DESCRIPTION: Install a bootloader for your system
:END:

In the main repository, there is efibootmgr and grub to serve as bootloaders.
efibootmgr can be used as a standalone bootloader, or can be used to install
grub in a UEFI environment. efibootmgr is needed unless you are using a device
without UEFI support (or you really want to use BIOS for a reason).

**** GRUB BIOS installation

#+BEGIN_EXAMPLE
  $ cpt b grub && cpt i grub
  $ grub-install --target=i386-pc /dev/sdX
  $ grub-mkconfig -o /boot/grub/grub.cfg
#+END_EXAMPLE

**** GRUB UEFI installation

#+BEGIN_EXAMPLE
  $ cpt b efibootmgr && cpt i efibootmgr
  $ cpt b grub && cpt i grub

  $ grub-install --target=x86_64-efi \
                 --efi-directory=esp \
                 --bootloader-id=CarbsLinux

  $ grub-mkconfig -o /boot/grub/grub.cfg
#+END_EXAMPLE

*** Init scripts
:PROPERTIES:
:DESCRIPTION: Install init scripts for your system
:END:

Only thing left to do is installing the init-scripts, and now you are almost
ready to boot your system!

#+BEGIN_EXAMPLE
  $ cpt b carbs-init && cpt i carbs-init
#+END_EXAMPLE

*** Fstab
:PROPERTIES:
:DESCRIPTION: Generating fstab
:END:

You can now manually edit your fstab entry, or you can use the genfstab tool.
If you want to use the tool, exit the chroot and run the following:

#+BEGIN_EXAMPLE
  $ wget https://github.com/cemkeylan/genfstab/raw/master/genfstab
  $ chmod +x genfstab
  $ ./genfstab -U /mnt >> /mnt/etc/fstab
#+END_EXAMPLE

** Post-installation
:PROPERTIES:
:DESCRIPTION: Post-installation tasks
:END:

The base installation is now complete, you can now fine tune your system
according to your needs. Rest of these instructions are completely optional.
You can check the rest of the documentation to learn more about the system.

*** KISS repositories
:PROPERTIES:
:DESCRIPTION: Acquire kiss repositories
:END:

While not 100% compatible with cpt, you can use kiss repositories in your
system the same way you are using the distribution repositories. Here is an
example for the KISS Linux Community repository.

* Package Manager
:PROPERTIES:
:DESCRIPTION: Carbs Packaging Tools
:END:

Carbs Linux uses its own package managing toolchain named =cpt=. It is a fork of
the [[https://github.com/kisslinux/kiss][kiss]] package manager. Unlike =kiss=, however, its main goal is being easily
extendable. Instead of being a single file package manager, it revolves around
the shell library =cpt-lib=, and many tools that wrap around it.

The full documentation of =cpt-lib= is incomplete, but will be added to the
[[https://github.com/CarbsLinux/cpt][package manager's own source]].

** Usage
:PROPERTIES:
:DESCRIPTION: Basic usage of Carbs Packaging Tools
:END:

=cpt= is formed of many tools combined in a single environment, similar to
=git=. When you run =cpt= without any arguments, it will show all available
tools and their explanations. Here is an example call with extra scripts on my
system:

#+BEGIN_EXAMPLE
  -> Carbs Packaging Tool
  -> add               Commit the current directory as a new package
  -> alternatives      List and swap to alternatives
  -> build             Build a package
  -> bump              Commit the current directory as a version bump
  -> cargo-urlgen      Create static cargo sources for Rust packages
  -> cargolock-urlgen  Convert the given Cargo.lock file to sources
  -> cat               Concatanate package files in the installed package database
  -> changelog         Print the git log of the specific package
  -> chbuild           Create/destroy temporary chroots
  -> checkmissing      Verify package manifests
  -> checksum          Generate checksums
  -> chroot            Enter a chroot
  -> commit            Commit a package without the prefix of 'package:'
  -> depends           Display a package's dependencies
  -> download          Download sources for the given package
  -> exec              Execute a command inside the alternatives system
  -> export            Turn an installed package into a CPT tarball
  -> fork              Fork a package to the current directory
  -> getchoice         Prints the full path to a file in the alternatives system.
  -> install           Install a package
  -> link              Link a forked package's files to the other repository
  -> list              List installed packages
  -> maintainer        Find the maintainer of a package
  -> manifest          Display all files owned by a package
  -> manifest-tree     Display all files owned by a package with a tree view
  -> new               Create a boilerplate CPT package
  -> orphans           List orphaned packages
  -> owns              Check which package owns a file
  -> rel               Bump the release number of a package
  -> remove            Remove a package
  -> repodepends       Display a package's dependencies in the repository
  -> reporevdepends    Display packages on the repository which depend on package
  -> reset             Remove all packages except for the base
  -> revdepends        Display packages which depend on package
  -> search            Search for a package
  -> size              Show the size on disk for a package
  -> source            Extract sources of a given package to the current directory
  -> update            Check for updates
#+END_EXAMPLE

*** =cpt-alternatives=
:PROPERTIES:
:DESCRIPTION: List and swap to alternatives
:END:

You can list and swap to alternatives using =cpt-alternatives=, or
=cpt a= for short. When run without alternatives, it will list
alternatives. It can read from standard input if =-= is given as an
argument.

**** Examples

List alternatives.

#+BEGIN_EXAMPLE
  $ cpt-alternatives
  ncurses /usr/bin/clear
  ncurses /usr/bin/reset
#+END_EXAMPLE

Swap to =clear= from =ncurses=.

#+BEGIN_EXAMPLE
  $ cpt-alternatives ncurses /usr/bin/clear
  -> Swapping '/usr/bin/clear' from 'busybox' to 'ncurses'
#+END_EXAMPLE

Swap in bulk (all of =sbase=).

#+BEGIN_EXAMPLE
  $ cpt a | grep ^sbase | cpt a -
#+END_EXAMPLE

*** =cpt-build=
:PROPERTIES:
:DESCRIPTION: Build a package
:END:

=cpt-build= will build given packages and their dependencies. If multiple
packages are specified, it will ask to install the packages as well.

| Flags          | Explanation  |
|----------------+--------------|
| =-t=, =--test= | Run tests    |

*** =cpt-checksum=
:PROPERTIES:
:DESCRIPTION: Generate checksums
:END:

=cpt-checksum= will generate a =checksums= file from the package's sources.

*** =cpt-download=
:PROPERTIES:
:DESCRIPTION: Download sources for the given package
:END:

=cpt-download= will download the sources of a package.

*** =cpt-install=
:PROPERTIES:
:DESCRIPTION: Install a package
:END:

=cpt-install= will install given packages.

*** =cpt-list=

When called without arguments, =cpt-list= will print all installed
packages. You can add package names as arguments to check whether they are
installed or not. In success, =cpt-list= will exit with status 0 if all
given packages are installed, it will return 1 if any of the given packages
aren't installed.

| Flags             | Explanation                            |
|-------------------+----------------------------------------|
| =-c=, =--current= | Use the current directory as a package |

*** =cpt-remove=
:PROPERTIES:
:DESCRIPTION: Remove a package
:END:

=cpt-remove= will remove given packages.

*** =cpt-search=
:PROPERTIES:
:DESCRIPTION: Search for a package
:END:

=cpt-search= will search for packages, it accepts regular expressions as well.

| Flags            | Explanation                               |
|------------------+-------------------------------------------|
| =-s=, =--single= | Only show the first instance of a package |


#+BEGIN_EXAMPLE
  $ cpt-search 'alsa-*'
  /var/db/cpt/repo/extra/alsa-lib
  /var/db/cpt/repo/extra/alsa-utils
  /var/db/cpt/installed/alsa-lib
  /var/db/cpt/installed/alsa-utils

  $ cpt-search emacs
  /home/cem/repos/main/community/emacs
  /home/cem/repos/kiss-community/community/emacs
  /var/db/cpt/installed/emacs

  $ cpt-search --single emacs
  /home/cem/repos/main/community/emacs
#+END_EXAMPLE


*** =cpt-update=
:PROPERTIES:
:DESCRIPTION: Check for updates
:END:

=cpt-update= will update the packages on your system. It fetches remote
repositories, and builds, and installs packages that have versions different
from the ones installed on the system. It doesn't check if the version string
is actually higher, it only checks whether they differ.

| Flags                | Explanation                          |
|----------------------+--------------------------------------|
| =-d=, =--download=   | Only download updatable packages     |
| =-n=, =--no-fetch=   | Do not update remote repositories    |
| =-o=, =--only-fetch= | Only fetch the repositories and exit |


*** Global Flags
:PROPERTIES:
:DESCRIPTION: Flags that work globally on some cpt utilities
:END:

| Flags               | Explanation                      |
|---------------------+----------------------------------|
| =-f=, =--force=     | Force operation, [[=CPT_FORCE=][See =CPT_FORCE=]] |
| =-y=, =--no-prompt= | Do not prompt for confirmation   |
| =-root CPT_ROOT=    | Use an alternate root directory  |
| =-h=, =--help=      | Show this help message           |
| =-v=, =--version=   | Print version information        |

** Environment Variables
:PROPERTIES:
:DESCRIPTION: Change the behaviour of cpt through environment configuration
:END:

Since there is no configuration file for cpt, the package manager is configured
through environment variables. These can be set per operation, or be set to your
shell configuration or =~/.profile=. Here are the environment variables that
alter the behaviour of =cpt=:

| ENVIRONMENT VALUE | Effects                                                                       |
|-------------------+-------------------------------------------------------------------------------|
| =CPT_PATH=        | Set the locations of your repositories. It is similar to the =PATH= variable. |
| =XDG_CACHE_HOME=  | Unless this is set, the =~/.cache= directory will be used instead.            |
| =CPT_CACHE=       | The cache directory for =cpt=. Default: =$XDG_CACHE_HOME/cpt=                 |
| =CPT_CHOICE=      | If this is set to 0, a package installation will be aborted on conflicts.     |
| =CPT_COMPRESS=    | Program used to compress package tarballs. [[=CPT_COMPRESS=][See =CPT_COMPRESS=]]                 |
| =CPT_DEBUG=       | If set to 1, temporary directories will not be removed after the operation.   |
| =CPT_FETCH=       | If set to 0, =cpt-update= will not fetch repositories.                        |
| =CPT_FORCE=       | [[=CPT_FORCE=][See =CPT_FORCE=]]                                                               |
| =CPT_HOOK=        | Location for the hook file.                                                   |
| =CPT_KEEPLOG=     | If set to 1, cpt will keep logs regardless of operation success.              |
| =CPT_PID=         | [[=CPT_PID=][See =CPT_PID=]]                                                                 |
| =CPT_PROMPT0=     | If set to 0, =cpt= will not prompt you for anything.                          |
| =CPT_ROOT=        | If this variable is set, =cpt= will assume this as the system root.           |
| =CPT_TEST=        | If set to 1, =cpt-build= will run tests whenever available.                   |
| =CPT_TMPDIR=      | The directory to create the temporary directories.                            |


*** =CPT_COMPRESS=
:PROPERTIES:
:DESCRIPTION: Compression tool to use in cpt
:END:

When setting the =CPT_COMPRESS= value, you should set the name of the default
suffixes for the program. Available values are:

- =gz=
- =zst=
- =bz2=
- =xz=

Defaults to =gz=.

*** =CPT_FORCE=
:PROPERTIES:
:DESCRIPTION: Force operations on cpt
:END:

If this is set to 1, some of the =cpt= tools will continue regardless of
errors or skip certain checks. Here are some examples:

- =cpt-install= will install a package without verifying its manifest.
- =cpt-install= will install a package even when there are missing dependencies.
- =cpt-remove= will remove packages even when there are other packages that
  depend on the current package.

Defaults to 0.

*** =CPT_PID=
:PROPERTIES:
:DESCRIPTION: Set reproducible temporary directories
:END:

If this variable is set, the temporary files will be created with this variable
as the suffix, instead of the PID of the =cpt= process. The advantage is that
you can know exactly where the build directory is located, while the
disadvantage is that there will be issues with multiple operations at the same
time. So the best way to use this variable is during one-time =cpt= calls.

#+BEGIN_EXAMPLE
  CPT_PID=mesa cpt b mesa
#+END_EXAMPLE

By running the above, you will know that the created build directories will end
with the =*-mesa= suffix.

** Hooks
:PROPERTIES:
:DESCRIPTION: Use hooks to customize the package manager operations
:END:

Hooks can be used in order to change the runtime behaviour of the package manager.
There are a variety of package hooks, mostly self explanatory:

- pre-build
- post-build
- build-fail
- pre-test
- test-fail
- pre-install
- post-install
- pre-remove
- post-remove
- pre-fetch
- post-fetch
- post-package

In order to use hooks, you will need to set the =CPT_HOOK= variable pointing to
your hook file. Your hook file *MUST* be a POSIX shell script as its contents
are sourced by the package manager.

The hook is given 3 variables when it is executed. Those are:

| Variable | Explanation                                                  |
|----------+--------------------------------------------------------------|
| =$TYPE=  | The type of the hook, (=pre-build=, =post-build=, etc.)      |
| =$PKG=   | The package that =cpt= is currently working on. Can be null. |
| =$DEST=  | The destination of the operation. Can be null.               |

*** Editing the =build= file during pre-build
:PROPERTIES:
:DESCRIPTION: Modify a package build with your hooks
:END:

You can edit the =build= file during pre-build. The file is copied from the
repository to the build directory named as =.build.cpt=. You can use =sed= or
any other tool to edit the build file. After the build is complete, a =diff=
file will be placed to the package database named as =build.diff=. Here is an
example =build= file manipulation during the pre-build hook.

#+BEGIN_SRC sh
  cat <<EOF> .build.cpt
  #!/bin/sh -e

  for patch in bash50-0??; do
      patch -p0 < "\$patch"
  done

  export LDFLAGS=-static

  ./configure \
      --prefix=/usr \
      --without-bash-malloc \
      --disable-nls

  export MAKEFLAGS="TERMCAP_LIB=/usr/lib/libncursesw.a $MAKEFLAGS"

  make
  make DESTDIR="\$1" install

  ln -s bash "\$1/usr/bin/sh"
  EOF
#+END_SRC

** Packaging System
:PROPERTIES:
:DESCRIPTION: More detail on creating packages
:END:

A package is formed of several files, these are:

- =build=
- =sources=
- =checksums=
- =version=
- =depends=
- =post-install=
- =message=
- =test=

Any other file can be added to the package directory at the discretion of the
package maintainer. Everything in the package directory will also be added to the
package database that is located on =/var/db/cpt/installed=. These can be
patches, configuration files, etc.

*** =build=
:PROPERTIES:
:DESCRIPTION: The build script
:END:

Typically =build= files are shell scripts that run commands to prepare the source
code to be installed on the target system. Even though we will be assuming that
the =build= file is a POSIX shell script (for portability's sake), =build=
files can be any executable program from binary programs to =perl= scripts.

The contents of a build script do not need to follow a certain rule for the
package manager, except for the fact that the user needs the permission to
execute the file.

An important advice is to append an '-e' to the shebang (#!/bin/sh -e) so that
the build script exits on compilation error.

Build is run with three arguments (=$#=)

- Location of the package directory (DESTDIR)
- Package version
- System architecture

*** =sources=
:PROPERTIES:
:DESCRIPTION: The file containing package sources
:END:

=sources= file is a list of files and sources that will be put to the build
directory during the build process. Those can be remote sources (such as tarballs),
git repositories, and files that reside on the package directory.

The syntax is pretty simple for the =soures= file; =src dest=. The =dest=
parameter is optional. It is the directory that the source will be placed in.
Here is the =sources= file for the =gst-plugins= package:

#+BEGIN_EXAMPLE
  https://gstreamer.freedesktop.org/src/gst-plugins-good/gst-plugins-good-1.16.2.tar.xz good
  https://gstreamer.freedesktop.org/src/gst-plugins-bad/gst-plugins-bad-1.16.2.tar.xz   bad
  https://gstreamer.freedesktop.org/src/gst-plugins-ugly/gst-plugins-ugly-1.16.2.tar.xz ugly
  https://gstreamer.freedesktop.org/src/gst-libav/gst-libav-1.16.2.tar.xz               libav
#+END_EXAMPLE

This file is read from the package manager as space seperated. Files that begin
with a =#= comment are ignored. The first value points to the location of the
source.

If it starts with a protcol url, (such as ftp:// http:// https://) it will be
downloaded with =curl=.

If the source is a git repository, it shall be prefixed with a =git+= git(1) will
be used to do a shallow clone of the repository. If the commit is suffixed by a
history pointer, git will checkout the relevant revision. So,

- =git+git://example.com/pub/repo@v1.2.3= :: will checkout the tag named "v1.2.3"
- =git+git://example.com/pub/repo#development= :: will checkout the branch named "development"
- =git+git://example.com/pub/repo#1a314s87= :: will checkout the commit named "1a314s87"

Other files are assumed to be residing in the package directory. They should be
added with their paths relative to the package directory.

*** =checksums=
:PROPERTIES:
:DESCRIPTION: The file containing sha256sum of the sources
:END:

checksums file is generated by the =cpt c pkg= command. It is generated
according to the order of the sources file. That's why you shouldn't be editing
it manually. The checksums file is created with the digests of the files using
the sha256 algorithm.

*** =version=
:PROPERTIES:
:DESCRIPTION: The file containing the version and the release numbers of a package
:END:

The version file includes the version of the software and the release number of
of the package on a space seperated format. The contents of the file should look
like below.

#+BEGIN_EXAMPLE
  1.3.2 1
#+END_EXAMPLE

*** =depends=
:PROPERTIES:
:DESCRIPTION: The file containing the dependencies of a package
:END:

This is a list of dependencies that must be installed before a package build. You
can append "make" after a dependency to mark a package is only required during
the build process of a package. Packages marked as a make dependency can be
removed after the build. There are also "test" dependencies. These dependencies
are only installed if either the =CPT_TEST= is set to 1, or the build is run
with the =-t= or =--test= options. So, a package package could have
the following =depends= file:

#+BEGIN_EXAMPLE
  linux-headers make
  python        test
  zlib
#+END_EXAMPLE

*** =post-install=
:PROPERTIES:
:DESCRIPTION: The post-installation script
:END:

=post-install= files have the same requirements as the build script. They
will be run after the package is installed as root (or as the user if the user
has write permissions on =CPT_ROOT=).

*** =message=
:PROPERTIES:
:DESCRIPTION: The post-installation message to be displayed
:END:

This plaintext file will be outputted with =cat= after every package is
installed.

*** =test=
:PROPERTIES:
:DESCRIPTION: The test script for a package
:END:

Test files are mainly for the repository maintainer to test the packages, and
will only run if the user has the =CPT_TEST= variable set, or the build is
run with the =-t= or =--test= options. This script is run on the
build directory. It is run right after the build script is finished.

** Rsync Repositories
:PROPERTIES:
:DESCRIPTION: Information on using or creating rsync repositories
:END:

Rsync repositories are simple to serve and simple to use. In the repository
directory, there needs to be a =.rsync= file that points to the remote of the
repository. This is used in order to fetch changes from the upstream. =.rsync=
file looks like this for the core repository:

#+BEGIN_EXAMPLE
  rsync://carbslinux.org/repo/core
#+END_EXAMPLE

Rsync repositories have some few distinctions when it comes to fetching them.
They can be either synced individually or as a "root". There are 2 important
files, those are =.rsync= and =.rsync_root=. Here is the Carbs Linux
rsync repository structure.

#+BEGIN_EXAMPLE
             /
     -----------------
    |                |
  .rsync           core/
            ----------------
            |              |
          .rsync      .rsync_root
#+END_EXAMPLE

Unlike git repositories, they don't have a defined "root" directory. This is
both an advantage and a disadvantage. This way, we can sync individual
repositories, but that also means we need extra files to define root directories
and repository locations. Here is the content for each of these files:

#+BEGIN_EXAMPLE
  /.rsync:           rsync://carbslinux.org/repo
  /core/.rsync:      rsync://carbslinux.org/repo/core
  /core/.rsync_root: ..
#+END_EXAMPLE

The =.rsync_root= file on the core repository points to the upper directory.
If a =.rsync= file exists on the upper directory, this means that is the whole
repository and will sync the entire repository instead of each individual repository.

If the upper directory doesn't have this =.rsync= file, this means that this
is an individual repository, and the package manager will fetch accordingly.

*** Setting up an Rsync repository
:PROPERTIES:
:DESCRIPTION: Set up a repository for distribution
:END:

Carbs Linux repositories automatically sync from the git repostitories and serve
it through the rsync daemon. Here is a sample shell script that I use in order to
sync repositories. Feel free to customize for your own use.

#+BEGIN_SRC sh
  #!/bin/sh
  HOSTNAME="rsync://carbslinux.org/repo"
  GITDIR="/pub/git/repo"
  SHAREDIR="/pub/share/repo"
  git -C "$GITDIR" pull

  rsync -avcC --delete --include=core --exclude=.rsync,.rsync_root "$GITDIR/." "$SHAREDIR"

  printf '%s\n' "$HOSTNAME" > "$GITDIR/.rsync"
  for dir in "$GITDIR/"*; do
      [ -d "$dir" ] || continue
      [ -f "$dir/.rsync" ] ||
      printf '%s/%s\n' "$HOSTNAME" "${dir##*/}" > "$dir/.rsync"
      printf '..\n' > "$dir/.rsync_root"
  done
#+END_SRC

You can then create an *rsync* user for serving the repositories.

#+BEGIN_EXAMPLE
  $ adduser -SD rsync
#+END_EXAMPLE

Create =/etc/rsyncd.conf= and a service configuration as well.


#+BEGIN_EXAMPLE
  uid = rsync
  gid = rsync
  address = example.com
  max connections = 10
  use chroot = yes

  [repo]
      path = /pub/share/repo
      comment = My repository
#+END_EXAMPLE

Create a service file at =/etc/sv/rsync/run= (runit):

#+BEGIN_SRC sh
  #!/bin/sh -e
  exec rsync --daemon --no-detach
#+END_SRC

* Init System
:PROPERTIES:
:DESCRIPTION: Configure the init system
:END:

Carbs Linux init scripts are run by the init daemon (=busybox= by default) on
boot and shutdown processes. It also provides its own halting program named
shalt. This provides a portable method that doesn't rely on non-POSIX external
programs.

** Configuring Init
:PROPERTIES:
:DESCRIPTION: Ways to configure the init system
:END:

There are three ways you can change the behaviour of the init system. Those are:

- Kernel Command Line
- =/etc/init/rc.conf= file
- Init Hooks

*** Kernel Command Line
:PROPERTIES:
:DESCRIPTION: Configure init through the boot parameters
:END:

On GRUB, you can edit the kernel command line parameters, which will be parsed
as variables on the init system. Not all of the parameters will be acted upon,
but all of them will be set as variables on the init script. For example an
example command line, and how it is interpreted.

#+BEGIN_EXAMPLE
  BOOT_IMAGE=/boot/vmlinuz root=/dev/sda2 rw loglevel=3 quiet
#+END_EXAMPLE

This command line will be parsed to set the following variables:

#+BEGIN_EXAMPLE
  BOOT_IMAGE=/boot/vmlinuz
  root=/dev/sda2
  rw=1
  loglevel=3
  quiet=1
#+END_EXAMPLE

Some of these variables, such as =rw=/=ro=, =loglevel=, and =quiet=, will be
used by the init system to change the behaviour of the startup.

*** =/etc/init/rc.conf= file
:PROPERTIES:
:DESCRIPTION: Configure init through the configuration file
:END:

However, the kernel command line isn't the only place to set your boot
parameters. You can specify variables here as well, although note that the
kernel command line always gets the priority for these variables since they can
be set just before boot.

*** Init Hooks
:PROPERTIES:
:DESCRIPTION: Configure init through hooks
:END:

Init hooks are for custom personal commands that the user may want to add to
alter their boot. These can be used to load kernel modules, modify interfaces,
and lot more. Those hooks are added to the =/etc/init= directory with the
hook name as the suffix. For example, a boot script will be placed as
=/etc/init/my-hook.boot=. Currently, there are 4 hooks that the user can use.

- early-boot :: Run after pseudo-filesystems are mounted.
- boot :: Run before the boot stage is completed.
- pre.shutdown :: Run first when shutting down.
- umount :: Run just before filesystems are unmounted.
- post.shutdown :: Run just before the system is halted.

** Changing Init Program
:PROPERTIES:
:DESCRIPTION: Replace the default busybox init with something new
:END:

By default, Carbs Linux comes preinstalled with =busybox-init=, but this can
easily be replaced without any issues. Currently, available init systems are:

- =sinit=
- =busybox=
- =runit=
- =shinit=

This example is for runit, but it will work with all init systems packaged in the
distribution repositories. [[=cpt-alternatives=][See =cpt-alternatives=]]

#+BEGIN_EXAMPLE
  $ cpt a runit /usr/bin/init
  $ cpt a runit /usr/bin/poweroff
  $ cpt a runit /usr/bin/reboot
#+END_EXAMPLE

*** Rebooting after changing init
:PROPERTIES:
:DESCRIPTION: Ways to reboot after replacing the init system
:END:

After switching init systems, your running init system may not accept the
new poweroff commands. You will need to reboot/poweroff using the running init's
utilities for the new utilities to work. These commands are for the init system
currently running on your system and not the one you are switching to.

| Program      | Command          |
|--------------+------------------|
| busybox      | =busybox reboot= |
| runit        | =runit-init 6=   |
| shinit/sinit | =kill -s INT 1=  |

* Contribution Guidelines
:PROPERTIES:
:DESCRIPTION: Contribute to Carbs Linux
:END:

Thanks for taking your time to contribute! To maintain stylistic behaviour
throughout the repositories, one must adhere to these conventions. Exceptions
and changes may occur with good reasoning.

** Conventions
:PROPERTIES:
:DESCRIPTION: Conventions of the distribution
:END:

#+TEXINFO: @macro contid{id}
#+TEXINFO: [@anchor{\id\}\id\]
#+TEXINFO: @end macro

#+TEXINFO: @macro sectid{id, sect}
#+TEXINFO: @strong{@contid{\id\} \sect\}
#+TEXINFO: @end macro

- {{{contid(0010)}}} :: Try to keep the file readable.
  - {{{contid(0011)}}} :: Characters on a line shouldn't exceed 100 characters.
  - {{{contid(0012)}}} :: Make sure you don't have code commented out during
    commit. Uncomment them or remove them completely.
  - {{{contid(0013)}}} :: Do not add comments following the code, add them to the
    top of the code. It makes it harder to read, and lines longer. Here is an example:

  #+BEGIN_EXAMPLE
    # Good way of commenting.
    your code goes here

    your code goes here  # Avoid this way of commenting.
  #+END_EXAMPLE

*** Shell Conventions
:PROPERTIES:
:DESCRIPTION: Conventions for shell scripts
:END:

Shell is central to Carbs Linux projects. Most of the tools and packages are
written in POSIX sh.

- {{{contid(1010)}}} :: Use 4 spaces for indentation, don't use tabs.
- {{{contid(1020)}}} :: Make sure you don't use bash-specific code.
- {{{contid(1030)}}} :: Make sure you lint your code with =shellcheck= and if
  you are new to POSIX sh, use =checkbashisms=.
- {{{contid(1040)}}} :: Don't spawn new processes if you don't absolutely need
  to, especially during string manipulation.
  - {{{contid(1041)}}} :: Never use a program for text manupilation that isn't
    defined in the POSIX standard. This includes =gawk= and =perl=.
  - {{{contid(1042)}}} :: Instead of ~$(basename $file)~, use ~${file##*}~.
  - {{{contid(1043)}}} :: Instead of ~$(dirname $file)~, use ~${file%/*}~.

  #+BEGIN_EXAMPLE
    # This is the same thing as basename /path/to/test.asc .asc

    $ file=/path/to/test.asc file=${file##*/} file=${file%.asc}
    $ echo $file
    test
  #+END_EXAMPLE
- {{{contid(1050)}}} :: Instead of backticks, use ~$(..)~.

*** Repository Conventions
:PROPERTIES:
:DESCRIPTION: Conventions for repository build scripts
:END:

Repository conventions are important in order to ensure every package resemble
themselves. Here are the things to keep in mind:

- {{{contid(2010)}}} :: Prefer tarballs over git packages unless there is a
  sensible reason. Here are some:
  - Every patch is a new release. (See [[https://github.com/vim/vim][vim]])
  - There are no releases. (See [[https://git.suckless.org/sbase][sbase]])
  - Following a development branch.
  - There has been a long time since the latest release, but upstream is far
    ahead.
- {{{contid(2020)}}} :: Prefer sources without a dependency to =automake=. There
  are usually distribution tarballs that are =autoconf='ed. Don't submit tarballs
  with an automake dependency unless you are =sure= there is no alternative.
- {{{contid(2030)}}} :: Avoid these packages:
  - dbus    :: Usually can be disabled by ~--disable-dbus~.
  - gettext :: Usually can be disabled by ~--disable-nls~.
- {{{contid(2040)}}} ::
  - Always install a package to the =/usr= prefix.
  - All binaries should go to =/usr/bin=, not =/usr/sbin= or any other directory.
  - All libraries should go to =/usr/lib=.
- {{{contid(2050)}}} :: All build files on the repository should be a POSIX
  shell script, and must start with ~#!/bin/sh -e~.

The next section is about package templates that should be used in order to
ensure stylistic consistency. Note that the option configurations shouldn't be
taken literally, they are meant as examples.

**** {{{sectid(2210, Make)}}}

#+BEGIN_SRC sh
  #!/bin/sh -e

  make
  make DESTDIR="$1" PREFIX=/usr install
#+END_SRC

**** {{{sectid(2211, Configure/Make)}}}

#+BEGIN_SRC sh
  #!/bin/sh -e

  ./configure \
      --prefix=/usr \
      --disable-option \
      --enable-option

  make
  make DESTDIR="$1" install
#+END_SRC

**** {{{sectid(2212, Autoconf/Automake)}}}

#+TEXINFO: @xref{2020}

#+BEGIN_SRC sh
  #!/bin/sh -e

  autoreconf -fi

  ./configure \
      --prefix=/usr \
      --disable-option \
      --enable-option

  make
  make DESTDIR="$1" install
#+END_SRC

**** {{{sectid(2220, Meson)}}}

#+BEGIN_SRC sh
  #!/bin/sh -e

  export DESTDIR=$1

  meson \
      --prefix=/usr \
      -Doption=false \
      -Doption2=true \
      . output

  ninja -C output
  ninja -C output install
#+END_SRC

**** {{{sectid(2230, Cmake)}}}

#+BEGIN_SRC sh
  #!/bin/sh -e

  export DESTDIR=$1

  cmake -B build \
      -DCMAKE_INSTALL_PREFIX=/usr \
      -DCMAKE_BUILD_TYPE=Release \
      -DOPTION=ON

  cmake --build   build
  cmake --install build
#+END_SRC

**** {{{sectid(2240, Go)}}}

#+BEGIN_SRC sh
  #!/bin/sh -e

  export GOPATH=$PWD/gopath
  trap "go clean -modcache" EXIT INT
  go mod vendor

  go build
  install -Dm755 program "$1/usr/bin/program"
#+END_SRC

**** {{{sectid(2241, Python)}}}

#+BEGIN_SRC sh
  #!/bin/sh -e

  python setup.py build
  python setup.py install --prefix=/usr --root="$1"
#+END_SRC

* GNU Free Documentation License
:PROPERTIES:
:APPENDIX: t
:DESCRIPTION: Your rights
:END:

#+INCLUDE: fdl.org