@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