@subsection Goals

This section exists to organize files related to @file{centos-art.sh}

script @samp{verify} functionality.  The @samp{verify}

functionality of @file{centos-art.sh} script helps you to verify the

workstation configuration you are planning to use as host for your

working copy of CentOS Artwork Repository.

@subsection Description

The first time you download CentOS Artwork Repository you need to

configure your workstation in order to use @file{centos-art.sh}

script.  These preliminar configurations are based mainly on auxiliar

RPM packages installation, symbolic links creations, and environment

variables definitions.  The @samp{verify} functionality of

@file{centos-art.sh} script guides you through this preliminar

configuration process.  

If this is the first time you run @file{centos-art.sh} script, the

appropriate way to use its @samp{verify} functionality is not using

the @file{centos-art.sh} script directly, but the absolute path to

@command{centos-art.sh} script instead (i.e.,

@file{~/artwork/trunk/Scripts/Bash/centos-art.sh}).  This is necessary

because @file{centos-art} symbolic link, under @file{~/bin/}

directory, has not been created yet.

@subsubsection Packages

Installation of auxiliar RPM packages provides the software required

to manipulate files inside the repository (e.g., image files,

documentation files, translation files, script files, etc.). Most of

RPM packages @command{centos-art.sh} script uses are shipped with

CentOS distribution, and can be installed from CentOS base repository.

The only exception is @samp{inkscape}, the package we use to

manipulate SVG files.  The @samp{inkscape} package is not inside

CentOS distribution so it needs to be installed from third party

repositories.

@quotation

@strong{Note} Configuration of third party repositories inside CentOS

distribution is described in CentOS wiki, specifically in the

following URL:

@url{http://wiki.centos.org/AdditionalResources/Repositories}

@end quotation

Before installing packages, the @file{centos-art.sh} script uses

@command{sudo} to request root privileges to execute @command{yum}

installation functionality.  If your user isn't defined as a

privileged user---at least to run @command{yum} commands--- inside

@file{/etc/sudoers} configuration file, you will not be able to

perform package installation tasks as set in @file{centos-art.sh}

script @samp{verify} functionality. 

Setting sudo privileges to users is an administrative task you have to

do by yourself. If you don't have experience with @command{sudo}

command, please read its man page running the command: @command{man

sudo}. This reading will be very useful, and with some practice, you

will be able to configure your users to have @command{sudo}

privileges.

@subsubsection Links

Creation of symbolic links helps us to alternate between different

implementations of @file{centos-art.sh} script-line (e.g.,

@file{centos-art.sh}, for Bash implementation; @file{centos-art.py},

for Python implementation; @file{centos-art.pl}, for Perl

implementation; and so on for other implementations). The

@file{centos-art.sh} script-line definition takes place inside your

personal binary (@file{~/bin/}) directory in order to make the script

implementation ---the one that @file{centos-art} links to--- available

to @var{PATH} environment variable.

Creation of symbolic links helps us to reuse components from repository

working copy. For example, color information files maintained inside

your working copy must never be duplicated inside program-specific

configuration directories that uses them in your workstation (e.g.,

Gimp, Inkscape, etc.).  Instead, a symbolic link must be created for

each one of them, from program-specific configuration directories to

files in the working copy.  In this configuration, when someone

commits changes to color information files up to central repository,

they---the changes committed--- will be immediatly available to your

programs the next time you update your working copy ---the place

inside your workstation those color information files are stored---.

Creation of symbolic links helps us to make @file{centos-art.sh}

script functionalities available outside @file{trunk/} repository

directory structure, but at its same level in repository tree. This is

useful if you need to use the ``render'' functionality of

@command{centos-art.sh} under @file{branches/} repository directory

structure as you usually do inside @file{trunk/} repository directory

structure. As consequence of this configuration, automation scripts

cannot be branched under @file{branches/Scripts} directory structure.

@subsubsection Environment variables

Definition of environemnt variables helps us to set default values to

our user session life. The user session environment variable defintion

takes place in the user's @file{~/.bash_profile} file.  The

@samp{verify} functionality of @file{centos-art.sh} script doesn't

modify your @file{~/.bash_profile} file.  

The @samp{verify} functionality of @file{centos-art.sh} script

evaluates the following environment variables:

@table @env

@item EDITOR

Default text editor. 

The @file{centos-art.sh} script uses default text @env{EDITOR} to edit

pre-commit subversion messages, translation files, configuration

files, script files, and similar text-based files.

If @env{EDITOR} environment variable is not set, @file{centos-art.sh}

script uses @file{/usr/bin/vim} as default text editor. Otherwise, the

following values are recognized by @file{centos-art.sh} script:

@itemize

@item @file{/usr/bin/vim}

@item @file{/usr/bin/emacs}

@item @file{/usr/bin/nano}

@end itemize

If no one of these values is set in @env{EDITOR} environment variable,

@file{centos-art.sh} uses @file{/usr/bin/vim} text editor by default. 

@item TEXTDOMAIN

Default domain used to retrieve translated messages.  This variable is

set in @file{initFunctions.sh} and shouldn't be changed.

@item TEXTDOMAINDIR

Default directory used to retrieve translated messages.  This variable

is set in @file{initFunctions.sh} and shouldn't be changed.

@item LANG

Default locale information.

This variable is initially set in the configuration process of CentOS

distribution installer (i.e., Anaconda), specifically in the

@samp{Language} step; or once installed using the

@command{system-config-language} tool.

The @file{centos-art.sh} script uses the @var{LANG} environment

variable to know in which language the script messages are printed

out.

@item TZ

Default time zone representation.

This variable is initially set in the configuration process of CentOS

distribution installer (i.e., Anaconda), specifically in the

@samp{Date and time} step; or once installed using the

@command{system-config-date} tool.

The @file{centos-art.sh} script doesn't use the @var{TZ} environment

variable information at all. Instead, this variable is used by the

system shell to show the time information according to your phisical

location on planet Earth.  

Inside your computer, the time information is firstly set in the BIOS

clock (which may need correction), and later in the configuration

process of CentOS distribution installer (or later, by any of the

related configuration tools inside CentOS distribution).  Generally,

setting time information is a straight-forward task and configuration

tools available do cover most relevant location. However, if you need

a time precision not provided by the configuration tools available

inside CentOS distribution then, using @var{TZ} variable may be

necessary.

@quotation

@strong{Convenction} In order to keep changes syncronized between

central repository and its working copies: configure both repository

server and workstations (i.e., the place where each working copy is

set on) to use Coordinated Universal Time (UTC) as base time

representation.  Later, correct the time information for your specific

location using time zone correction.

@end quotation

The format of @var{TZ} environment variable is described in

@file{tzset(3)} manual page.

@end table

@subsection Usage

@table @command

@item centos-art verify --packages

Verify required packages your workstation needs in order to run the

@file{centos-art.sh} script correctly.  If there are missing packages,

the @file{centos-art.sh} script asks you to confirm their

installation. When installing packages, the @file{centos-art.sh}

script uses the @command{yum} application in order to achieve the

task.

In case all packages required by @file{centos-art.sh} script are

already installed in your workstation, the message @samp{The required

packages are already installed.} is output for you to know. 

@item centos-art verify --links

Verify required links your workstation needs in order to run the

centos-art command correctly.  If any required link is missing, the

@command{centos-art.sh} script asks you to confirm their installation.

To install required links, the @command{centos-art.sh} script uses the

@command{ln} command.

In case all links required by @file{centos-art.sh} script are already

created in your workstation, the message @samp{The required links are

already installed.} is output for you to know. 

In case a regular file exists with the same name of a required link,

the @file{centos-art.sh} script outputs the @samp{Already exists as

regular file.} message when listing required links that will be

installed. Of course, as there is already a regular file where must be

a link, no link is created. In such cases the @file{centos-art.sh}

script will fall into a continue installation request for that missing

link.  To end this continue request you can answer @samp{No}, or

remove the existent regular file to let @file{centos-art.sh} script

install the link on its place.

@item centos-art verify --environment

@itemx centos-art verify --environment --filter='regex'

Output a brief description of environment variables used by

@file{centos-art.sh} script. 

If @samp{--filter} option is provided, output is reduced as defined in

the @samp{regex} regular expression value. If @samp{--filter} option

is specified but @samp{regex} value is not, the @file{centos-art.sh}

script outputs information as if @samp{--filter} option had not been

provided at all.  

@end table

@subsection See also

@menu

* trunk Scripts Bash::

* trunk Scripts Bash Functions::

@end menu