@subheading Goals

This section exists to organize files related to @file{centos-art.sh}
script @samp{prepare} functionality.  The @samp{prepare} functionality
of @file{centos-art.sh} script helps you to prepare the workstation
configuration you are planning to use as host for your working copy of
CentOS Artwork Repository.

@subheading 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{prepare} 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{prepare} 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.

@subsubheading 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{prepare} 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.

@subsubheading 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.

@subsubheading 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{prepare} functionality of @file{centos-art.sh} script doesn't
modify your @file{~/.bash_profile} file.  

The @samp{prepare} 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

@subsubheading Shell Script Files

The @code{shell} functionality of @file{centos-art.sh} script helps
you to maintain bash scripts inside repository. For example, suppose
you've created many functionalities for @file{centos-art.sh} script,
and you want to use a common copyright and license note for
consistency in all your script files. If you have a bunch of files,
doing this one by one wouldn't be a big deal. In contrast, if the
amount of files grows, updating the copyright and license note for all
of them would be a task rather tedious. The @code{shell} functionality
exists to solve maintainance tasks just as the one previously
mentioned.

When you use @code{shell} functionality to update copyright inside
script files, it is required that your script files contain (at least)
the following top commentary structure:

@verbatim
 1| #!/bin/bash
 2| #
 3| # doSomething.sh -- The function description goes here.
 4| # 
 5| # Copyright
 6| #
 7| # ...
 8| #
 9| # ----------------------------------------------------------------------
10| # $Id$
11| # ----------------------------------------------------------------------
12|
13| function doSomething {
14|     
15| }
@end verbatim

Relevant lines in the above structure are lines from 5 to 9.
Everything else in the file is left immutable.

When you are updating copyright through @code{shell}
functionality,  the @file{centos-art.sh} script replaces everything
in-between line 5 ---the first one matching @samp{^# Copyright .+$}
string--- and line 9---the first long dash separator matching @samp{^#
-+$}--- with the content of copyright template instance.

@quotation
@strong{Caution} Be sure to add the long dash separator that matches
@samp{^# -+$} regular expression @emph{before} the function
definition. Otherwise, if the @samp{Copyright} line is present but no
long dash separator exists, @file{centos-art.sh} will remove anything
in-between the @samp{Copyright} line and the end of file. This way you
may lost your function definitions entirely.
@end quotation

The copyright template instance is created from one copyright template
stored in the @file{Config/tpl_forCopyright.sed} file.  The template
instance is created once, and later removed when no longer needed. At
this moment, when template instance is created, the
@file{centos-art.sh} script takes advantage of automation in order to
set copyright full name and date dynamically.

When you use @code{shell} functionality to update copyright, the first
thing @file{shell} functionality does is requesting copyright
information to user, and later, if values were left empty (i.e., no
value was typed before pressing @key{RET} key), the @file{shell}
functionality uses its own default values.

When @code{shell} functionality uses its own default values, the final
copyright note looks like the following:

@verbatim
 1| #!/bin/bash
 2| #
 3| # doSomthing.sh -- The function description goes here.
 4| #
 5| # Copyright (C) 2003, 2010 The CentOS Project
 6| # 
 7| # This program is free software; you can redistribute it and/or modify
 8| # it under the terms of the GNU General Public License as published by
 9| # the Free Software Foundation; either version 2 of the License, or
10| # (at your option) any later version.
11| # 
12| # This program is distributed in the hope that it will be useful, but
13| # WITHOUT ANY WARRANTY; without even the implied warranty of
14| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15| # General Public License for more details.
16| #
17| # You should have received a copy of the GNU General Public License
18| # along with this program; if not, write to the Free Software
19| # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
20| # USA.
21| #
22| # ----------------------------------------------------------------------
23| # $Id$
24| # ----------------------------------------------------------------------
25|
26| function doSomething {
27|
28| }
@end verbatim

Relevant lines in the above structure are lines from 5 to 22.  Pay
attention how the copyright line was built, and how the license was
added into the top comment where previously was just three dots.
Everything else in the file was left immutable. 

To change copyright information (i.e., full name or year information),
run the @code{shell} functionality over the root directory containing
the script files you want to update copyright in and enter the
appropriate information when it be requested. You can run the
@code{shell} functionality as many times as you need to.

To change copyright license (i.e., the text in-between lines 7 and
20), you need to edit the @file{Config/tpl_forCopyright.sed} file, set
the appropriate information, and run the @code{shell} functionality
once again for changes to take effect over the files you specify.

@quotation
@strong{Important} The @file{centos-art.sh} script is released as: 

@verbatim
GNU GENERAL PUBLIC LICENSE
Version 2, June 1991

Copyright (C) 1989, 1991 Free Software Foundation, Inc.
                         675 Mass Ave, Cambridge, MA 02139, USA
@end verbatim

Do not change the license information under which @file{centos-art.sh}
script is released. Instead, if you think a different license must be
used, please share your reasons at @email{centos-devel@@centos-art.sh}
mailing list.

See file
@url{file:///home/centos/artwork/trunk/Scripts/COPYING,trunk/Scripts/COPYING},
for a complete license description.
@end quotation

@subsubheading SVG Files

The @code{svg} functionality of @file{centos-art.sh} script helps you
to maintain scalable vector graphics (SVG) inside repository. For
example, suppose you've been working in CentOS default design models
under @file{trunk/Identity/Themes/Models/}, and you want to set common
metadata to all of them, and later remove all unused SVG defintions
from @samp{*.svg} files. Doing so file by file may be a tedious task,
so the @file{centos-art.sh} script provides the @code{svg}
functionality to aid you maintain such actions.

The metadata used is defined by Inkscape 0.46 using the SVG standard
markup. The @file{centos-art.sh} script replaces everything
in-between @code{<metadata} and @code{</metadata>} tags with a
predefined metadata template we've set for this purpose.

The metadata template was created using the metadata information of a
file which, using Inkscape 0.46, all metadata fields were set. This
created a complete markup representation of how SVG metadata would
look like. Later, we replaced every single static value with a
translation marker in the form @samp{=SOMETEXT=}, where
@code{SOMETEXT} is the name of its main opening tag. Later, we
transform the metadata template into a sed replacement set of commads
escaping new lines at the end of each line.

With metadata template in place, the @file{centos-art.sh} script uses
it to create a metadata template instance for the file being processed
currently.  The metadata template instance contains the metadata
portion of sed replacement commands with translation markers already
traduced.  In this action, instance creation, is where we take
advantage of automation and generate metadata values like title, date,
keywords, source, identifier, and relation dynamically, based on the
file path @file{centos-art.sh} script is currently creating metadata
information for.

With metadata template instance in place, the @file{centos-art.sh}
script uses it to replace real values inside all @samp{.svg} files
under the current location you're running the @file{centos-art.sh}
script on.  Default behaviour is to ask user to enter each metadatum
required, one by one. If user leaves metadatum empty, by pressing
@key{RET} key, @file{centos-art.sh} uses its default value.

Many of the no-longer-used gradients, patterns, and markers (more
precisely, those which you edited manually) remain in the
corresponding palettes and can be reused for new objects. However if
you want to optimize your document, use the @samp{Vacuum Defs} command
in @samp{File} menu. It will remove any gradients, patterns, or
markers which are not used by anything in the document, making the
file smaller. 

If you have one or two couple of files, removing unused definitions
using the graphical interface may be enough to you.  In contrast, if
you have dozens or even houndreds of scalable vector graphics files to
maintain it is not a fun task to use the graphical interface to remove
unused definitions editing those files one by one.

To remove unused definitions from several scalable vector graphics
files, the @file{centos-art.sh} script uses Inkscape command-line
interface, specifically with the @option{--vaccum-defs} option.

@subsubheading XHTML Files

@subheading Usage

@table @command

@item centos-art prepare --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 prepare --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 prepare --environment
@itemx centos-art prepare --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

@subheading See also

@menu
* Directories trunk Scripts::
* Directories trunk Scripts Functions::
@end menu