Package management

Introduction

This section describes the package system introduced in the Dragora 2.x series.

Introduction

Dragora's package system was written from scratch making use of the features and advantages of the command language interpreter, BASH. It is simply called "pkgsystem".

It contains the command line tools to build, install, remove and upgrade software packages. The files format have the .tlz extension and they use GNU tar for the packaging and Lzip as the compression format in the package redistribution.

The main command of the package system is called `pkg'. It is nothing more than a wrapper to execute the command line tools that belong to the list of commands of pkg.

Within each package - besides the system programs - includes a description in English and Spanish that can be shown on screen at the time of installing or updating the packages.

The format of the package system's database is maintained on plain text files.

Currently, by default, Dragora's package system does not offer automatic dependency resolution, since that would need more code and, in some cases, require complex algorithms. Those are more prone to failure than to resolution.

In summary, we want to refer to the package system as something simple, well done. Something that gives the control and the power to the user. We invite you to read about its usage in the paragraphs below.

Usage

Installing packages:

To install one or more packages we will use the command `pkg' followed by action we want to perform, in this case: add. For instance:

# pkg add pidgin-2.7.11-i486-1.tlz

Installing multiple packages:

# pkg add ktsuss-1.4-i486-1.tlz icewm-1.3.7-i486-1.tlz gimp-2.6.11-i486-1.tlz

Installing a package that had been previously installed:

# pkg add --force pidgin-2.7.11-i486-1.tlz

The option -f or --force in add overwrites an installed package.

Inspecting the content of a package:

# pkg add --warn xterm-270-i487-1.ltz

The option -w or --warn in add warns about the files and directories that will be installed or overwritten by the system.

Removing packages:

Removing one or more installed packages is fairly easy. To do it, we combine `pkg' with remove.

Removing a package by name:

# pkg remove pidgin

It is not necessary to specify the complete name or path of the package. remove can interpret the segments of the name of the package.

Removing a package by name and version:

As you can see, with two segments it is possible to remove a package:

# pkg remove pidgin-2.7.11

Removing multiple packages:

# pkg remove pidgin ktsuss-1.4 icewm gimp

Inspecting the content that would be removed:

# pkg remove --warn xterm

Removing a package getting rid of the output messages:

By default, remove shows the output of what it is removing (files, directories and symbolic links). It's possible to get rid of these messages using the option --quiet:

# pkg remove --quiet xterm

Use the option -q or --quiet in remove only if you know what you're doing.

Upgrading packages:

# pkg upgrade pidgin-2.8.1-i486-1.tlz

Upgrading many packages:

# pkg upgrade ktsuss-1.5-i486-1.tlz icewm-1.3.9-i486-1.tlz gimp-2.8.0-i486-1.tlz

Just like with add, upgrade requires the complete path or name of the package for it to work.
Upgrading a previously upgraded package:
# pkg upgrade -f pidgin-2.8.1-i486-1.tlz
Install a non-installed package, upgrading:
# pkg upgrade -i ironsword-6.6.6-i486-1.tlz
It is possible to install one or more (non-installed) packages on an upgrade.
Upgrading with details:
# pkg upgrade -v pidgin-2.8.1-i486-1.tlz
The option -v activates the verbose mode. This, at most, shows the output of remove.
Combining options:
# pkg upgrade -v -f pidgin-2.8.1-i486-1.tlz
It forces the upgrade showing in detail what's being removed.

Checking the size:

To see the size of the packages we use size. For instance, we type:

# pkg size pidgin-2.7.11-i486-1.tlz

And we get:

  Package = pidgin-2.7.11-i486-1.tlz
  Compressed size = 7.1M
  Uncompressed size = 36M

size can accept multiple packages.

Examining:

The debugging is done through erupt, which decompresses and unpackages the package file, resetting its permissions.

Uncompressing with erupt for debugging purposes:

# pkg erupt xterm-270-i486-1.tlz

If a directory is not specified, erupt decompresses the package in the present working directory. If one is specified, see what happens:
```
  # mkdir /tmp/erupt-xterm
  # pkg erupt xterm-270-i486-1.tlz /tmp/erupt-xterm
```
A directory named "erupt-xterm" has been created in the "tmp" directory, and then erupt was called specifying the target directory (/tmp/erupt-xterm) using erupt, where the package was decompressed for debugging purposes.

Database

The following is a description of the directory structure of the database:

Directory:	Description:
/var/db	Default directory of the database.
/var/db/pkg/pre-post	Directory for the pre-post instalation files.
/var/db/pkg/post-install	Directory for the post-installation files.
/var/db/pkg/description	Directory that contains the descriptions of the packages.
/var/db/pkg/removed	Secondary hierarchy where the removed files and directories reside.
/var/db/pkg/removed/pre-post	Removed files of pre-post instalation.
/var/db/pkg/removed/post-install	Removed files of post-instalation.
/var/db/pkg/removed/description	Removed description files.

Environment variables

There are two important environment variables for add, remove and upgrade. They are:

DB=

Indicates the directory where the parts of the database reside, by default: /var/db.

ROOT=

Root variable that can be used to install, remove or upgrade one or more packages in a previously mounted partition. For instance:

# ROOT=/mnt/hd pkg add xterm-270-x86_64-1.tlz

08 November 2011, 16:17 | pkgm.t2t - GNU Free Documentation License