February 2010 | Linux Blog

Installing Mozilla Firefox 3.6 on openSUSE 11.2

Firefox 3.6 is built on Mozilla's Gecko 1.9.2 web rendering platform, which has been under development since early 2009 and contains many improvements for web developers, add-on developers, and users. This version is also faster and more responsive than previous versions and has been optimized to run on small device operating systems such as Maemo.

Firefox 3.6 Installation on openSuSe 11.2:
Open YaST control center and click on Software Management

From the menu select Configuration and then select Repositories

Click on the Add button on the bottom of the window and select Specify URL in the window that opens and click on Next

Under the Repository Name, type Mozilla and enter the URL http://download.opensuse.org/repositories/mozilla/openSUSE_11.2/ under the URL field and click on Next and wait while the repository is being downloaded and added.

Now on the Software Management window enter the phrase firefox and click on search

Click on the result that has the summary as “Mozilla Firefox Web Browser” and click on Versions which appears directly below the search results pane.

Gbrainy - Brain Teaser Game for Linux

gbrainy is a brain teaser game and trainer to have fun and to keep your brain trained.

gbrainy provides the following types of games:

* Logic puzzles. Games designed to challenge your reasoning and thinking skills.
* Mental calculation. Games based on arithmetical operations designed to prove your mental calculation skills.
* Memory trainers. Games designed to challenge your short term memory.
* Verbal analogies. Games that challenge your verbal aptitude.

gbrainy provides different difficulty levels making gbrainy enjoyable for kids, adults or senior citizens. It also features player's game history, player's personal records, tips for the player, or fullscreen mode. gbrainy can be also extended easily with new games developed by third parties.

gbrainy is designed for GNOME and runs on top of GNU/Linux and different Unix flavours.

Download
Source code: gbrainy-1.30.tar.gz (md5sum 80135619a92a350434471c30832f6106)
Packages for Debian.
Packages for Ubuntu
Packages for Fedora (Also build with OpenSuse build service).
Packages for Suse.
Packages for Mandriva.

After successful installation go to terminal and type command: gbrainy to open up the application

How To Set $PATH Variable in Linux

When you type a command at the shell prompt, it has to be read off disk out of one or other directory. On Linux all such executable commands are located in one of the directories. A file is located in the directory tree according to its type, and not according to what software package it belongs to. Hence, for example, a word processor may have its actual executable stored in a directory with all other executables, while its font files are stored in a director with other fonts from all other packages.

The shell has a procedure for searching for executable when you type them in. If you type in a command with slashes, like /bin/cp then it tries to run the named program: cp out of the /bin directory. If you just type cp on its own, then it tries to find the cp command in each of the sub-directories of your PATH. To see what your PATH is, just type

echo $PATH

You will see a colon separated list of directories. Note that the current directory . is not listed. It is very important that the current directory not be listed for security reasons. To execute a command in the current directory, we hence always type ./.

To append for example a new directory /opt/gnome/bin to your PATH, do

PATH="$PATH:/opt/gnome/bin"
export PATH

you can also do this in one line: export PATH="$PATH:/opt/gnome/bin"

How to use Mac Fonts on Linux

Just follow these simple steps on installing and using Mac fonts onLinux.

Installing the fonts:
Open up the Linux terminal and download the Mac font files with this command:

$ wget http://ubuntu-debs.googlecode.com/files/macfonts.tar.gz

Extract the font files:

$ tar zxvf macfonts.tar.gz

Move the extracted fonts directory to the system fonts directory

$ sudo mv macfonts /usr/share/fonts

Reload the font cache:

$ sudo fc-cache -f -v

Good Collection of Linux Tutorials

Free Linux Tutorials for Beginners
    * Introduction to Linux – This IBM tutorial is designed for people who want to learn what Linux is and how it can be used.
    * Linux Desktop 101 – This 14-week course teaches students how to run the Linux operating system on a PC.
    * Hands-On Introduction to Linux – Machtelt Garrels’ well-organized tutorial provides a hands-on introduction to Linux.
    * Real Time Linux Introduction – A series of introductory Linux tutorials from the National Institute of Standards and Technology.
    * Getting Started with Linux – This 20-lesson course from Linux Online is designed for people who are just getting started with Linux.
    * Linux Fundamentals Course – The Shuttleworth Foundation’s fundamentals course takes approximately 18 hours to complete and gives students a basic understanding of the Linux operating system.
    * The 35-Command Tutorial – This basic Linux tutorial from BeginLinux.org teaches 35 commands that every Linux user should know.
    * Getting Started with Linux Desktop – Novell’s self-study course teaches basic Linux desktop skills.

Free Linux Tutorials for Experts
    * Linux Online’s Course for Advanced Users – This advanced course from Linux Online is fashioned into a series of how-to documents. Designed for people who want to learn more about installation, configuration and maintenance tasks.
    * Linux System Administration Course – This 28-module course provides comprehensive training for system administrators.
    * Kernel Tutorials – The kernel tutorials at HowToForge are a great way for Linux users to learn everything they need to know about kernels.
    * Advanced Routing and Traffic Control Tutorial – This advanced Linux tutorial teaches users about routing, filtering and traffic shaping.
    * Linux Enterprise Server Courses – Novell Training Services offers several different courses for advanced Linux users.
    * Linux Network Administration Course – The Shuttleworth Foundation’s Linux Network Administration Course is split into separate tutorials that teach the fundamentals of network administration.
    * Advanced Linux Programming – This tutorial is actually a book that can be downloaded for free. The book teaches users how to develop Linux software and write sophisticated programming.
    * IBM’s Technical Library – IBM’s Technical Library offers a number of useful tutorials for advanced Linux users.

Few more over here
Ubuntu Tips, Tricks and tutorials - here
Linux related e-books - Free - here

PyMT - Library for developing multi-touch applications

PyMT is an open source library for developing multi-touch applications. It is completely cross platform (Linux/OSX/Win) and released under the terms of the GNU LGPL.

It comes with native support for many multi-touch input devices, a growing library of multi-touch aware widgets, hardware accelerated OpenGL drawing, and an architecture that is designed to let you focus on building custom and highly interactive applications as quickly and easily as possible.

Since PyMT is a pure Python library, you can take advantage of its highly dynamic nature and use any of the thousands of high quality and open source python libraries out there.

Documentation
API documentation - Pure-API pages.
Wiki documentation - the most up-to-date documentation content
Programming Guide - how to start with toolkit

Install PyMT on Ubuntu:

First, install all needed packages :

sudo apt-get install python-setuptools python-pygame python-opengl python-numpy python-gst0.10 python-cairo python-imaging gstreamer0.10-plugins-good

Then install the PyMT package : sudo easy_install pymt

How To Secure your SSH Server

One security tweak you need to consider is with Open-SSH server. By default, direct logon for root is enabled, which means your just asking for trouble with hackers attempting to break into your Computer. Instead, you can easily disable root access from logging into your SSH server,

Disable Root Access
you'll need to edit the /etc/ssh/sshd_config file using your favorite editor

Once gedit or kate opens, scroll down until you see the following section…

LoginGraceTime 120
PermitRootLogin yes
StrictModes yes

Modify PermitRootLogin as shown below:

PermitRootLogin no

This will disable root's access to logon via SSH. Save the file and exit gedit.

Now you'll need to restart the sshd service from a Terminal window using the following command: /etc/init.d/sshd restart

After restarting SSH, try to connect using the root account. Access should be disallowed and you should only be able to log on with your user account. Once you do login, you can access the root account by using the su command.

Decrease SSH Login Grace Time
Another security option you may want to consider, is to lower the LoginGraceTime parameter to about 30 seconds.

LoginGraceTime 30

The login grace time is a period of time where a user may be connected but has not begun the authentication process. By default, sshd will allow a connected user to wait 120 seconds (2 minutes) before starting to authenticate.

By shortening this time, you can decrease the chances of someone attempting a brute force attack against your SSH server from being successfull.

Allow Certain Users SSH Access
By default, SSH will permit every user with an account SSH access. To prevent this, you can use the AllowUsers command to allow access to certain users.

To do this, add the following line in your sshd configuration file under the Authentication section.

AllowUsers usera userb

This will allow only users usera and userb access to login via SSH.

After making the above changes, save the file sshd_config. To allow the changes to become effective immediately, don't forget to restart SSH by running the following command from a Terminal window: /etc/init.d/sshd restart

By making these simple changes to your SSH configuration, it will allow you to increase security by opening up access to your computer for authorized users…and closing the door on hackers.

openSUSE Survey 2010 – Participate now

Participate in the openSUSE survey 2010 to give feedback to the openSUSE project about the distribution, the openSUSE tools environment and the project in general. Let the project know where things are in good shape and areas where improvement is needed.

There are also some questions to get some demographic knowledge about users. The survey will take about 8 mins.

The survey will be online till Feb 28, 2010 and openSUSE project raffle amongst all participants some t-shirts, openSUSE 11.2 boxes and 1 one really neat device (most probably a Chumby). If you wanna participate in the raffle please provide your email address at the end, if not just skip it.

FSArchiver - Filesystem Archiver for Linux

FSArchiver is a system tool that allows you to save the contents of a filesystem to a compressed archive file. The filesystem can be restored on a partition that has a different size, and it can be restored on a different filesystem. Unlike tar/dar, fsarchiver also creates the filesystem when it extracts the data to partitions. Everything is checksummed in the archive in order to protect the data. If the archive is corrupt, you just lose the current file, not the whole archive.

FSArchiver can extract an archive to a partition which is smaller that the original one as long as there is enough space to store the data. It can also restore the data on a different file-system, so it can use it when you want to convert your file-system: you can backup an ext3 file-system, and restore it as a reiserfs.

FSArchiver is working at the file level. It can make an archive of filesystems (ext3, ext4, reiserfs, xfs, ntfs, ...) that the running kernel can mount with a read-write support. It will preserve all the standard file attributes (permissions, timestamps, symbolic-links, hard-links, extended-attributes, ...), as long as the kernel has support for it enabled. It can also be used to archive and extract ntfs filesystems.

Installation:
OpenSuSe user can install FSArchiver using "1-click" installer - here
Fedora user can install FSArchiver using yum: yum install fsarchiver

Here is how to use FSArchiver to backup a partition of your disk partition. Let's consider you want to take backup of on /dev/sda8 and you want to back it up to a file on /mnt/backup. You can run this command from terminal:

# fsarchiver savefs -v -a /mnt/backup/nikesh.fsa /dev/sda8

Here is how to restore a filesystem from an archive when there is only one filesystem in that archive:

# fsarchiver restfs /mnt/backup/nikesh.fsa id=7,dest=/dev/sda8

Grsync - A Graphical User Interface for Rsync

Grsync is a rsync GUI (Graphical User Interface). Rsync is the well-known and powerful command line directory and file synchronization tool. Grsync makes use of the GTK libraries and is released under the GPL license.

Grsync doesn't need the gnome libraries to run, but can of course run under gnome pretty fine. It can be effectively used to synchronize local directories and it supports remote targets as well (even though it doesn't support browsing the remote folder).

Sample uses of grsync include:
    Synchronize a music collection with removable devices
    Backup personal files to a networked drive
    Replication of a partition to another one
    Mirroring of files, etc.

Installation:
OpenSuSe user can install Grsync using "1-click" installer - here
To install on CentOS or Fedora: yum install grsync

Open GRsync and create a new session. Choose the source folder location in the first box and the target folder in the second box. Then you can configure the options below.

Move on to the advanced options tab. The most important part here is the “additional options” section. Here you can specify anything else you want to pass to rsync.

APG - Automated Password Generator for random password generation

APG (Automated Password Generator) is the tool set for random password generation. This standalone version generates some random words of required type and prints them to standard output.

Advantages:
   * Built-in password quality checking system (it has support for Bloom filter for faster access)
   * Two Password Generation Algorithms:
           Pronounceable Password Generation Algorithm
           Random Character Password Generation Algorithm
    * Configurable password length parameters
    * Configurable amount of generated passwords
    * Ability to initialize RNG with user string
    * Support for /dev/random
    * Ability to crypt() generated passwords and print them as additional output.
    * Special parameters to use APG in script
    * Ability to log password generation requests for network version
    * Ability to control APG service access using tcpd
    * Ability to enforce remote users to use only allowed type of password generation

Installation:
OpenSuSe user can install apg using "1-click" installer - here

apg usage:
Command apg -a 1 -M n -n 3 -m 8 -E 23456789 will generate a set of passwords that will look like this
0000010001
1001010001
011101101

Command apg -a 1 -M nc -n 3 -m 26 -E GHIJKLMNOPQRSTUVWXYZ will generate a set of passwords that will look like this
8DE4FE0FA76F19CF32BE75AF0D
F1597A2854E4DCBDB4FCF6E9E6
C7F1C7226D7EA21F1BCEE3CE07

Command apg -t -n 6 -x 8 will generate a set of passwords that will look like this
gegwefra (geg-we-fra)
fredjid2 (fred-jid-TWO)
BiHaynOf (Bi-Hayn-Of)
andinPeg (and-in-Peg)
donVejNa (don-Vej-Na)
zananOs1 (zan-an-Os-ONE)

Look at the apg man pages for more such options.

How to Import / Export (Backup / Restore) MySQL Database

It is important to back up your databases so that you can recover your data and be up and running again in case problems occur. MySQL offers a variety of backup strategies from which you can choose the methods that best suit the requirements for your installation.

Export / Backup MySQL database:
The mysqldump client can be used to dump a database or a collection of databases for backup or for transferring the data to another SQL server (not necessarily a MySQL server). The dump contains SQL statements to create the table and/or populate the table.

If you are doing a backup on the server, and your tables all are MyISAM tables, you could consider using the mysqlhotcopy instead since faster backups and faster restores can be accomplished with the latter

Here is the most simple way to export the database to a sql file

# mysqldump -u USER -p DATABASE > FILENAME.sql

USER is the MySQL admin user
DATABASE is the name of the database that need to be exported
FILENAME.sql is the name of the file where your data will be exported

When you issue this command you will be prompted for the MySQL admin password. Enter that password and hit the Enter key. In the directory you issued the command you will now have a file with the FILENAME.sql file you then need to copy to your secure drive.

You can dump all databases by doing:

# mysqldump -u root -p --all-databases > all_dbs.sql

Import/Restore MySQL database:
Below is the simple command through which you can restore / import the already exported MySQL database file (.sql)

# mysql -u USER -p DATABASE < FILENAME.sql

USER is the MySQL admin user
DATABASE is the name of the database where data need to be imported / restore
FILENAME.sql is the dump that was exported.

You will be prompted for the MySQL administrator password.

Astyle - Source code indenter, formatter, and beautifier for C, C++, C# and Java

Astyle (Artistic Style) is a source code indenter, formatter, and beautifier for the C, C++, C# and Java programming languages.

When indenting source code, programmers have a tendency to use both spaces and tab characters to create the wanted indentation. Moreover, some editors by default insert spaces instead of tabs when pressing the tab key, and other editors (Emacs for example) have the ability to "pretty up" lines by automatically setting up the white space before the code on the line, possibly inserting spaces in a code that up to now used only tabs for indentation.

Since the NUMBER of space characters showed on screen for each tab character in the source code changes between editors (unless the user sets up the number to his liking...), one of the standard problems programmers are facing when moving from one editor to another is that code containing both spaces and tabs that was up to now perfectly indented, suddenly becomes a mess to look at when changing to another editor. Even if you as a programmer take care to ONLY use spaces or tabs, looking at other people's source code can still be problematic.

To address this problem, Artistic Style was created - a filter written in C++ that automatically re-indents and re-formats C / C++ / C# / Java source files. It can be used from a command line, or it can be incorporated as classes in another C++ program.

Installation:
OpenSuSe user can install Astyle using "1-click" installer - here

Using Astyle:
If you have never used Artistic Style there are a couple of ways to start. One is to run it with no options at all. This will format the file with 4 spaces per indent and will leave the brackets unchanged. Another is to use one of the predefined styles described in the "Predefined Style Options" section (below). Select one with a bracket formatting style you like. Once you are familiar with the options you can customize the format to your personal preference.

Predefined Styling options:
--style=ansi ANSI style formatting/indenting.
--style=kr Kernighan&Ritchie style formatting/indenting.
--style=gnu GNU style formatting/indenting.
--style=java Java mode, with standard java style formatting/indenting.
--style=linux Linux mode (i.e. 8 spaces per indent, break definition-block brackets but attach command-block brackets.

Example to format a single file:
astyle --style=allman /home/user/project/foo.cpp

Example to format all .cpp and .h files recursively:
astyle --style=allman --recursive /home/user/project/*.cpp /home/user/project/*.h

Check out the Astyle documentation for many more options.

PDFCrack - A Password Recovery / Crack Tool for PDF-files on Linux

PDFCrack is a GNU/Linux (other POSIX-compatible systems should work too) tool for recovering passwords and content from PDF-files. It is small, command line driven without external dependencies. The application is Open Source (GPL).

Features:

Supports the standard security handler (revision 2, 3 and 4) on all known PDF-versions
Supports cracking both owner and userpasswords
Both wordlists and bruteforcing the password is supported
Simple permutations (currently only trying first character as Upper Case)
Save/Load a running job
Simple benchmarking
Optimised search for owner-password when user-password is known

Installation:
OpenSuSe user can install PDFCrack using "1-click" installer - here
Install pdfcrack on Ubuntu by typing: sudo aptitude install pdfcrack

Using PDFCrack:
Run a quick benchmark by entering the following at the command line:

pdfcrack -b

Use pdfcrack to crack an encrypted pdf-file by typing:

pdfcrack crack.pdf

iptstate - Display IPtables state information in a "top"-like interface

iptstate (IP Tables State) implements the "state top" feature from IP Filter for IP Tables. "State top" displays the states held by your stateful firewall in a "top"-like manner. Since IP Tables doesn't have a built-in way to easily display this information once, an option was added to iptstate to do this.

The only requirements are a curses library (usually ncurses), and libnetfilter_conntrack version 0.0.50 or later

Installation:
OpenSuSe user can install iptstate using "1-click" installer - here
Ubuntu user can install iptstate - here

After successful installation, go to terminal and type command: iptstate to open up the application and if netfilter CONNTRACK is enabled in the kernel.

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