9 Amazing Linux Command Line Games!

Tuesday, September 24, 2013:  It is a known fact that command line is the most powerful tool on Linux, but did you know that you can even play cool games here? And if you already knew you might be interested in trying out these cool games! Check out the 9 command line games and have fun!  


 

 





1. Arithmetic

A simple calculation game which can help your kids learn the basic calculations.

Run:

arithmetic

Install:

Sudo apt-get install bsdgames

2. Scribble

Yes the classic scribble is now on command line, time to kill some time on command line.

Run:

Scribble

Install:

Sudo apt-get install scribble

3. Backgammon

This is the command line, multi-player, version of the Backgammon game. It has got nice simple instructions for people that have never played backgammon and for people that have never used the command line version before. You can play against the computer or against a friend.

Run:

backgammon

Install:

Sudo apt-get install bsdgames

4. Worm

This is a growing worm game, from your first mobile is back to entertain you right on your commandline

Comands:
Arrow keys to move
Ctrl-c to exit

Run:

Worm

Install:

Sudo apt-get install bsdgames

5. Tetris

Yes, your childhood favourite has found its way to the command line.

Commands:
J: left
L: Right
K: Rotate
Space: Drop

Run:

tetris-bsd

Install:

Sudo apt-get install bsdgames

6. Monopoly

This game is also on the command line version, although there is no board bur it’s not bad as most people know how a monopoly board looks.

Commands:
Roll: to roll
M: mortgage property
?: for more commands

Run:

monop

Install:

Sudo apt-get install bsdgames

7. Greed

Before you play this game, we warn you that you might get addicted. The goal is to eat as many of the numbers as you can. If you land on a 5 then you will move 5 places in that direction.

Commands:
Arrow Keys: Move
?: Help

Run:

greed

Install:

sudo apt-get install greed

8. Ninvaders

Yes you got it right, this is the commandline version of space invaders!

Commands
Arrow Keys: Move
Space: Shoot

Run:

ninvaders

Install:

sudo apt-get install ninvaders

9. OverKill

Overkill is a death-match game full of blood which runs within the terminal. This game can only be run over a network against multiple players.

To install OverKill:

sudo apt-get install overkill

And use the following command to run the game:

xoverkill

Atithya Amaresh, EFYTIMES News Network 

Fonte: 9 Amazing Linux Command Line Games!

14 Less Known Facts About Linux

EFYTimes gives you a list of 14 such facts about Linux that are interesting and fun all at once.

Monday, September 16, 2013:  There are a lot of facts about Linux that are interesting and not known at all. EFYTimes gives you a list of 14 such facts about Linux that are interesting and fun all at once: 
 

1. Linux is Obsolete: One of the most heated debates on the relevance of Linux was held recently between Andrew S Tanenbaum and Linus Torvalds focused Linux portability and its architecture in general. Tanenbaum is of the opinion that the OS is obsolete.

2. The outspoken Linus: Linus Torvalds has been outspoken at many occasions-one of the more explicit comments he made recently was that he would not change the structure of Linux to “deep throat Microsoft”.

3. Was Linux invented by Bill Gates and has all the evidence removed by him? A compelling argument made by Mr Tom Adelstein on this topic. In his argument, he says that Microsoft has managed to show that smaller OS-es like Linux are a threat to its existence, and has managed to remove all the evidence as well!

4. Microsoft Linux AKA MSLinux: There has been talks of a Linux distribution system that tries to give the power of Linux with ease of use that one usually expect from Microsoft products. Most tech analysts say that they have a hard time believing this is true.

5. Linus was offered Job at Apple by Steve Jobs? This one’s absolutely correct. As far back as 2000, when Linus met Steve Jobs, he was offered a job at Apple’s Cupertino campus

6. GooBuntu: The Linux flavor used inside Google. This is also true that Ubuntu Linux is Google's desktop of choice and that it's called Goobuntu.

7. Linux for supercomputers: Linux powers 90 per cent of the world’s top supercomputers. World’s fastest super computer ‘Sequoia’ (developed by IBM) runs entirely on Linux.

8. Linux in movie making business: It is an interesting fact that 90 per cent of servers that are used by Hollywood animation studios make use of Linux.

9. The ‘Linux’ name trademark dispute: There was a trademark dispute which had gained some prominence when Linus decided to name kernel as ‘Linux’, especially given the fact that he didn’t register it. Later on, in 1994, a guy named William Della Croce, Jr. filed for a trademark in United States and demanded royalties from distributors of Linux. Linus Torvalds won this legal battle over name ‘Linux’ in 1997.

10. The first Linux Live CD: This was used by yggdrasil computing, a company, that was the first one to produce a Live-CD for it’s ‘Plug and Play’ Linux distribution known as LSX

11. Microsoft spends millions to counter Linux: It is believed on the back of firm evidence, that Bill Gates, the founder of Microsoft, spent $421 million to counter the growth of Linux and its penetration in Microsoft Windows’s market.

12. Linux as a case study: A now famous case study on Linux was part of an issue of the ‘Business Week Magazine’.

13. Hundreds of Linux Distros: Linux is distributed by over 300 distributions in action across the world and the list is growing everyday!

14. Linus, Steve and Bill Gates: Hate them or love them but we cannot ignore them. Here is a compilation of great quotes from these 3 men.

Fonte: 14 Less Known Facts About Linux

Important Shortcuts For Linux Beginners

Learning these shortcuts can make it very easy for beginners to learn Linux further.  

 Wednesday, August 21, 2013:  When working on Linux, there are some commands, which can make your life a lot simpler. Without them, life can be just as difficult

Ctrl + Alt + F1

You would already know that Linux can support various terminals. This command helps you move to the first terminal from wherever you are.

Ctrl + Alt + Fn (n=1..6)

In the standard setup, Linux can support a total of 6 terminals. This command lets you move to the terminal of your choice.

tty
This command is used to print the name of the terminal that you are currently using.

Ctrl + Alt + F7
This command is used to move to the graphical user interface terminal.

Ctrl + Alt + Fn (n=7..12)
This command helps the user go to the desired graphical user interface terminal. As a default setup, these terminals aren’t running anything, but one can use them to run a different server.

Tab
When you’re using a text terminal, you can use this command to autocomplete a command. If there is only one option, then the command is completed automatically, else it shows all the options that are available.

ArrowUp
This is used to scroll up and edit the command history. You need to press enter in order to execute this.

Shift + PgUp
This one scrolls the terminal output upwards. It also works on the login prompt, thereby allowing the user to scroll through whatever messages there are during bootup.

Shift + PgDown
Same as above, just scroll downwards.

Ctrl + Alt + +
In the X-windows system, this command is used to change the resolution of the next X-server, if it has been set to multiple resolutions.

Ctrl + Alt + -
This is the opposite of the above command. You use this to change to the previousX-server resolution.

Ctrl + Alt + BkSpc
In the event that the X-windows server that you were using has crashed and there is no way to exit it, this command helps you kill the said X-windows server in such a situation.

Ctrl + Alt + Del
When you’re at the text-mode console, this is the normal shut down command. It shuts the system down and reboots it.

Ctrl + c
This command shuts down the process that is currently running.

Ctrl + d
This command is used in order to logout from the terminal that you are on.

Ctrl + d
This command sends the [End-of-file] to the process that is running. Pressing it twice makes you log out of the system as well.

Ctrl + s
You use this command if you want to stop a transfer to a terminal.

Ctrl + q
If the terminal you’re working on stops responding then this command can help resume the transfer to the said terminal.

Ctrl + z
This command is used to shift the process that is currently running to the background.

exit
This is an alternate command for ‘logout’. It is used to log out of the system.

reset
This command is used to restore to default setting, a terminal that is screwed up. This means that it is displaying odd characters. The command is sometimes invisible when you’re typing it.

MiddleMouseButton
This is how you carry out the copy-paste function in Linux. The command is used best when you have a Linux-enabled three button mouse.

~(tilde)
This command takes you back to the home directory.

. (dot)
This command is for the current directory. A command such as ./the_program is going to try and run the file the_program.

.. (two dots)
This command changes the current directory into the parent directory.

Source: UnixGuide

Prasid Banerjee, EFYTIMES News Network 

Fonte: Important Shortcuts For Linux Beginners

16 Power Tools For Linux Users

Linux can be a breeze if you know about the right tools. We take a look here at a list of valuable power tools for Linux users.  

Thursday, August 29, 2013:  Some Linux power tools that are quite useful for troubleshooting or saving yourself from further troubles. These tools enable you in doing things faster. Please see them listed below along with their descriptions and command for downloading them. 

1. FSlint – This tool is good for locating duplicate files, bad names, empty folders and other trash that you want to get rid of from your system. You can install this tool by using – sudo apt=get install fslint

2. TestDisk – As cited on penguininside.blogspot.in, this is a tool for undelete and recovery. It does not support ext4 as yet but many distributions are making use of ext3. You should install this tool for recovering important data on your disk. You can install this tool by using – sudo apt-get install testdisk

3. TrueCrypt – This tool adds an extra bit to your file security.

4. BleachBit – Everything is stored in Linux in the form of files with some being useless. This tool is useful for Linux applications with small storage spaces. You need to download it from elsewhere as Ubuntu repositories stock the older versions.

5. PalimpSet Disk Utility - This is a default utility for Disk Management in Fedora. It’s a great utility as a front-end to S.M.A.R.T. This tool allows you to monitor the health of your disk in an easy way. Developed by Redhat this utility can be installed with the help of the debian package manager/apt-get. You can install this tool by using – sudo apt-get install gnome-disk-utility

6. Gconf-Editor – This is a front-end to gconftool-2 command line utility, a gnome configuration tool. The use of this tool on command line can be a bit of a problem for novices as you cannot remember all the paths. This tool gives you a feel of the Windows Registry editor. You can install this tool by using – sudo apt-get install gconf-editor 

7. Eiciel – This is a really good ACL front-end for novices who are not good at CLI and don’t want to use it.

8. Guake – It’s a normal terminal with a varied feel and behavior adding a console akin to Quake or Unreal Tournament to your Linux desktop. You can spawn it on Linux by pressing F12 and not ~. This tool is really good for frequent console users saving them from opening, closing and handling gnome-terminal windows. You can install this tool by using – sudo apt-get install quake

9. Meld – When using different configuration files or program code, one needs a different viewer and patcher. This is a visual diff and merge tool. It allows you to compare two to three files and edit them. You can install this tool by using – sudo apt-get install meld

10. Wine – It’s one of the most famous programs. Please note that default repositories do not keep the latest version so you need to download this tool from elsewhere.

11. Glipper – This is the best Clipboard Manager for Linux that works as a Gnome Panel Applet. This cannot run anywhere else than Gnome Panel. It is quite flexible having certain exceptional features, which include Snippets, Actions etc.

12. AutoKey – You can use this to program your individual system wide shortcuts or abbreviations to any content like address, name or something that you need to type numerous times, assign shortcuts to operations and applications. You can install it by using – sudo apt-get install autokey

13. Conduit Synchronizer – This is still being developed and is part of the GNOME project. It is a synchronization application for GNOME allowing you to synchronize files, photos, emails, contacts, notes, calendar data and other types of personal information. You can synchronize that data with another computer, online service or electronic device. You can install it by using – sudo apt-get install conduit 

14. BackInTime – This is a back up tool for restoring utility. You can install this by using - sudo apt-get install backintime-gnomeOrsudo apt-get install backintime-kde

15. ClamTK – This is a great front-end tool to ClamAV. It is simpler than ClamTK and lives up to your expectations. You need to download it from elsewhere as Ubuntu repositories stock the older versions.

16. Gnome-Do – This is a really great launcher tool taking its aspiration from Mac OS X quick silver. This can be used as a dock or panel. You can launch anything just with a few keystrokes if you don’t like mouse or pointers. You need to download it from elsewhere as Ubuntu repositories stock the older versions.

 Tradução: Gabriel Costa

Fonte: 16 Power Tools For Linux Users

14 Tips For Linux Geeks

EFYTimes takes you through some tips if you are a hard core Linux fan... 


Tuesday, September 10, 2013:  An average Linux user is separable from the super-geeks based on the time and effort spent learning the kinds of hacks, tricks, tips and techniques that turn long jobs into a moment's work. EFYTimes takes you through some tips if you are one of those who loves the Linux OS:

1: Check processes not run by you: In case of an attack, even in an office environment, your best bet is to list all the processes on the box not being run by you!

ps aux | grep -v `whoami`

Or, to be a little more clever, why not just list the top ten time-wasters:

ps aux --sort=-%cpu | grep -m 11 -v `whoami`

2: Replacing same text in multiple files: In case you as a user want to replace in multiple locations you can run this:

perl -i -pe 's/Windows/Linux/;' test*

To replace the text Windows with Linux in all text files in current directory and down you can run this:

find . -name '*.txt' -print | xargs perl -pi -e's/Windows/Linux/ig' *.txt

Or if you prefer this will also work, but only on regular files:

find -type f -name '*.txt' -print0 | xargs --null perl -pi -e 's/Windows/Linux/'

3: Fix a wonky terminal: If you are in the unenviable position of having used less or cat to list a file, and ended up viewing binary instead, Send the terminal an initialisation command:

reset

and all will be well again.

4: Creating Mozilla keywords: A useful feature in Konqueror is the ability to type gg onion to do a Google search based on the word onion. The same kind of functionality can be achieved in Mozilla by first clicking on Bookmarks>Manage Bookmarks and then Add a New Bookmark.

5: Running multiple X sessions: If you share your Linux box with someone and don’t want to be constantly logging in and out, you can just start your computer in a graphical mode (runlevel 5), by simultaneously pressing the keys Control+Alt+F1 - you will get a login prompt. Insert your login and password and then execute:

startx -- :1

to get into your graphical environment. To go back to the previous user session, press Ctrl+Alt+F7, while to get yours back press Ctrl+Alt+F8.

6: Faster browsing: If you want to speed up your web browsing experience, start the KDE Control Center and choose System > KDE performance from the sidebar. You can now select to preload Konqueror instances. Effectively, this means that Konqueror is run on startup, but kept hidden until you try to use it.

7: Backup your website easily: If you want to back up a directory on a computer and only copy changed files to the backup computer instead of everything with each backup, you can use the rsync tool to do this. You will need an account on the remote computer that you are backing up from. Here is the command:

rsync -vare ssh jono@192.168.0.2:/home/jono/importantfiles/* /home/jono/backup/

8: Keeping your clock in time: This is the best way to synchronise your watch on your computer. You will need to install the ntpdate tool that is often included in the NTP package, and then you can synchronise with an NTP server:

ntpdate ntp.blueyonder.co.uk

9: Finding the biggest files: A common problem with computers is when you have a number of large files (such as audio/video clips) that you may want to get rid of. You can find the biggest files in the current directory with:

ls -lSrh

10: Nautilus shortcuts: This has a a few keyboard shortcuts that can have you flying through files:

Open a location - Ctrl+L
Open Parent folder - Ctrl+Up
Arrow keys navigate around current folder.

You can also customise the file icons with 'emblems'.

11: Defrag your databases: Whenever you change the structure of a MySQL database, or remove a lot of data from it, the files can become fragmented resulting in a loss of performance, particularly when running queries. Just remember any time you change the database to run the optimiser:

mysqlcheck -o 

12: Quicker emails: Don’t waste time in locating email clients. Press Alt+F2 to bring up the 'Run command' dialog. Type:

mailto:plop@ploppypants.com

Press return and KMail will automatically fire up, ready for your words of wisdom. You don't even need to fill in the entire email address. This also works for Internet addresses: try typing www.slashdot.org to launch Konqueror.

13: Save battery power: You are probably familiar with using hdparm for tuning a hard drive, but it can also save battery life on your laptop, or make life quieter for you by spinning down drives.

hdparm -y /dev/hdb

hdparm -Y /dev/hdb

hdparm -S 36 /dev/hdb

In order, these commands will: cause the drive to switch to Standby mode, switch to Sleep mode, and finally set the Automatic spindown timeout. This last includes a numeric variable, whose units are blocks of 5 seconds (for example, a value of 12 would equal one minute).

14: Wireless speed management: In order to maintain communications as the available signal fades, the radios need to transmit data at a slower rate. Normally, the radios attempt to work out the available signal on their own and automatically select the fastest possible speed.

In fringe areas with a barely adequate signal, packets may be needlessly lost while the radios continually renegotiate the link speed.


Fonte: 14 Tips For Linux Geeks

Keep Your Linux Server Secure With 15 Easy Ways

There are important things to know when it comes to Linux. Read on.

Monday, September 09, 2013:  Security is of prime importance in any situation. EFYTimes brings you 15 steps you can follow to ensure better security of your Linux server. 1. Encrypt Data Communication: Use passwords wherever possible to make your data more secure. Make use of scp, ssh, rsync, or sftp for file transfer. This can also be done if the user mounts remote server file system using special sshfs and fuse tools. Another tool is GnuPG, which allows the user to encrypt and sign data and communication, features a versatile key management system. Also, avoid making use of FTP, Telnet, And Rlogin / Rsh. The common solution to this problem is to use either OpenSSH , SFTP, or FTPS (FTP over SSL), which adds SSL or TLS encryption to FTP. Type the following command to delete NIS, rsh and other outdated service: # yum erase inetd xinetd ypserv tftp-server telnet-server rsh-serve 2. Minimise Software to Minimise Vulnerability: If you are one of those that wants to install all sorts of web services, you need to avoid installing unnecessary software to avoid vulnerabilities. Make use of the RPM package manager such as yum or apt-get and/or dpkg to review all installed set of software packages on a system. Delete all unwanted packages. # yum list installed # yum list packageName # yum remove packageName OR # dpkg –list # dpkg --info packageName # apt-get remove packageName 3. One Network Service Per System or VM Instance: Run different network services on separate servers or VM instance, limiting the number of other services that can be compromised. 4. Keep Linux Kernel and Software Up to Date: Make sure you apply all security patches. While Linux provides all necessary tools to keep your system updated, all security updates should be reviewed and applied as soon as possible. 5. Use Linux Security Extensions: If possible use SELinux and other Linux security extensions to enforce limitations on network and other programs. For example, SELinux provides a variety of security policies for Linux kernel. 6. User Accounts and Strong Password Policy: Make use of the useradd / usermod for the creation and maintenance of user accounts. Also ensure that you have a good password policy in place. Most importantly, you need to pick a password you can remember. The change command changes the number of days between password changes and the date of the last password change. This information is used by the system to determine when a user must change his/her password. The /etc/login.defs file defines the site-specific configuration for the shadow password suite including password aging configuration. To disable password aging, enter: chage -M 99999 userName To get password expiration information, enter: chage -l userName Finally, you can also edit the /etc/shadow file in the following fields: {userName}:{password}:{lastpasswdchanged}:{Minimum_days}:{Maximum_days}:{Warn}:{Inactive}:{Expire}: 7. Disable root Login: Never make the mistake of logging in as the root user. One can use sudo to execute root level commands as and when required. 8. Physical Server Security: Protection of Linux servers physical console access is of paramount importance. This can be done by configuring the BIOS and disable the booting from external devices such as DVDs / CDs / USB pen. Set BIOS and grub boot loader password to protect these settings. 9. Disable Unwanted Services: Disable all unnecessary services and daemons (services that runs in the background). You need to remove all unwanted services from the system start-up. Type the following command to list all services which are started at boot time in run level # 3: # chkconfig --list | grep '3:on' To disable service, enter: # service serviceName stop # chkconfig serviceName off 10. Delete X Windows: This isn’t even a requirement on the server, there isn’t any reason to run X Windows on your dedicated mail and Apache web server. The service can be disabled altogether or can be removed to work towards the improvement of server security and performance. Edit /etc/inittab and set run level to 3. Finally, remove X Windows system, enter: # yum groupremove “X Window System” 11. Configure Iptables and TCPWrappers: Iptables is a user space application program that allows you to configure the firewall (Netfilter) provided by the Linux kernel. Use firewall to filter out traffic and allow only necessary traffic. Also use the TCPWrappers a host-based networking ACL system to filter network access to Internet. You can prevent many denial of service attacks with the help of Iptables. 12. Linux Kernel /etc/sysctl.conf Hardening: /etc/sysctl.conf file is used to configure kernel parameters at runtime. Linux reads and applies settings from /etc/sysctl.conf at boot time. Sample /etc/sysctl.conf: # Turn on execshield kernel.exec-shield=1 kernel.randomize_va_space=1 # Enable IP spoofing protection net.ipv4.conf.all.rp_filter=1 # Disable IP source routing net.ipv4.conf.all.accept_source_route=0 # Ignoring broadcasts request net.ipv4.icmp_echo_ignore_broadcasts=1 net.ipv4.icmp_ignore_bogus_error_messages=1 # Make sure spoofed packets get logged net.ipv4.conf.all.log_martians = 1 13. Separate Disk Partitions: Separation of the operating system files from user files may result into a better and secure system. Make sure the following filesystems are mounted on separate partitions: /usr /home /var and /var/tmp /tmp 14. Turn Off IPv6: This gives users a new Internet layer of the TCP/IP protocol suite that replaces Internet Protocol version 4 (IPv4) and provides many benefits. Currently there are no good tools out which are able to check a system over network for IPv6 security issues. 15. Disable Unwanted SUID and SGID Binaries: All SUID/SGID bits enabled file can be misused when the SUID/SGID executable has a security problem or bug. All local or remote user can use such file. It is a good idea to find all such files. Use the find command as follows: #See all set user id files find / -perm +4000 # See all group id files find / -perm +2000 # Or combine both in a single command find / \( -perm -4000 -o -perm -2000 \) -print find / -path -prune -o -type f -perm +6000 -ls

Fonte: Keep Your Linux Server Secure With 15 Easy Ways

25 melhores aplicativos para Linux

 A shortlist of 25 best Linux apps keeping in mind the audience.

 

Tuesday, September 03, 2013:  Linux is undoubtedly the best and the most popular operating system being deployed in devices and systems worldwide. Here are the top 25 best Linux-based apps as voted by the readers. 

1. Nagios for Monitoring - This app is for free. Its license status is GPL. The app lies inactive on your computer system monitoring host resources and network services with the aim of notifying the admin in the event a problem arises. You can download the app from www.nagios.org

2. GIT for Version control- As cited on techradar.com, this app is for free. Its license status is GPLv2. After becoming the default revision control system for the kernel, the app has gained popularity and become easier than ever owing to sites like Github. You can download the app from www.git-scm.com

3. GIMP - This app is for free. Its license status is GPL. The app is well known and comes as a standard on most distributions. There are books that are being written about it and it is quite often offered as the free alternative to Adobe's Photoshop. It has three striking features which include –
a) A very robust set of tools, providing support for everything from sub-pixel sampling and custom brushes for painting, right through to advanced manipulation tools such as layers, channels and transformable paths.
b) It comes with a versatile plug-in and extension system allowing any task to be automated using a simple script that can be written once and then executed with ease by a majority of users.
c) The app has an active community of developers meaning that even where Gimp lacks important features, work is constantly ongoing to extend it and make it the best tool possible. You can download the app from www.gimp.org

4. VirtualBox for Virtualisation - This app is for free. Its license status is GPLv2. Owing to its guest additions package, the app is well integrated to the host system and very fast. This makes it quite simple to spin-up a new virtual machine with its GUI along with command line and remote configuration tools. You can download the app from www.virtualbox.org

5. World of Goo - This app is priced at $20 and is proprietary. A physics-based construction and puzzle game that's become widely regarded as one of the best indie games of the past decade. It features beautifully drawn, cartoonish graphics that are cheerful, uplifting and timeless. All it involves is dragging Goos together to form a structure, but it's addictive and lots of fun. The app can be downloaded the app from www.2dboy.com/games.php

6. Money Dance - This app is priced at $49.99 and is proprietary. The app helps you to stay on top of your finances. The app is very easy and provides a clear overview of upcoming bills, the status of various budgets (which it helps you to create) and informative graphs and reports. You can download the app from www.moneydance.com

7. Eclipse IDE – This is a free app. Its license status is Eclipse Public. The app is an excellent, stable IDE. The Content Assist feature of the app that uses auto-complete methods, types and fields, is great for forgetful coders or those working on complex codebases. The app also has automatically enforced coding styles and copy and paste traces making it perfect for team development. You can download the app from www.eclipse.org/eclipse/index.php

8. Tomboy – Organiser – This is a free app and its license status is LGPL. This app is a little cool for collecting and organizing notes. It provides support for basic formatting and has automatic saving. The app makes managing to-do lists or organising research notes on a complex project really simple. You can download the app from www.projects.gnome.org/tomboy

9. Selinux –Security – This is a free app and its license status is GPL. This app is integrated with Linux 2.6 allowing it to be configured to restrict resources available to users, programs and daemons very effectively. You can download the app from www.selinuxproject.org/page/Main_Page.

10. Deja-Dup -Back-up tool – This is a free app and its license status is GPLv3. This app is a very simple tool for carrying out backups automatically and off-site. Its interface has two buttons and the configuration details are straightforward supporting a great range of backup locations including Amazon S3, SSH and Windows Shares. You can download the app from www. live.gnome.org/DejaDup .

11. Chromuim - Web browser – This is a free browser and its license status is BSD. Google Chrome allows you to do many things in a better way compared to many other applications. The interface is kept free of tabs. All the tabs are in the title bar allowing you to focus on the content better. It is the fastest among all the browsers.

12. Ubuntu Software Centre – This is a free app and its license status is GPL. It goes to a certain extent in making Linux repositories as pleasant as other trendy 'app' stores that have appeared recently. You can download the app from www.ubuntu.com/ubuntu/features.

13. Amnesia The Dark Descent – This is a proprietary app and is priced at $20. This is the scariest survival horror game ever to have been made. You can download it from www.amnesiagame.com .

14. Pencil - Animation – This is a free app and its license status is GPL. The app makes traditional, hand-drawn animations along with bitmap and vector images. The finished animations can be exported as PNG or Flash. You can download this app from www.pencilanimation.org.

15. IRSSI -IRC client – This is a free app and its license status is GPL. This app helps you in freeing yourself from getting stuck on the command line. You can download the app from www.irssi.org

16. EMACS -Text editor - This is a free app and its license status is GPLv3. It is not only the most popular editor but also also a mail and news reader, project planner, calendar and much more. You can download the app from www.gnu.org/software/emacs.

17. Artha –Thesaurus - This is a free app and its license status is GPLv2. An off-line thesaurus based on WordNet. It can look up selected text at the press of a button and provides synonyms, antonyms, causes and much more. You can download the app from www.artha.sourceforge.net/wiki.

18. Banshee - Media player – This is a free app and its license status is MIT. This is a great media player with support for audio and video in any format. It is also a great support for portable devices. You can download the app from www.banshee.fm.

19. ZSNES -SNES emulator – This is a free app and its license status is GPLv2. This is an excellent emulator to run your favorite games, from Mario to Street Fighter to Final Fantasy. You can download the app from www.zsnes.com.

20. Empathy- Messaging program – This is a free app and its license status is GPL. This app allows you to chat with your friends irrespective of the platform they choose. The app supports a broad range of features on multiple networks that includes voice and video calling. You can download the app from www.live.gnome.org/Empathy.

21. Shotwell - Photo manager – This is a free app and its license status is LGPL. This is a stable and feature-rich photo manager. It automatically collects images according to date. Its handly tools also make it easy to remove red-eye, crop, and adjust the color levels in your photographs and the software also supports uploading your pictures to plenty of online services, including Facebook, Flickr and Picasa.
You can download this app from www.yorba.org/shotwell.

22. TOR - Anonymity network – This is a free app and its license status is BSD. The app protects you from traffic analysis, it acts like a network surveillance allowing third parties to make a detailed picture of your online habits. It encrypts your network traffic and routes it through a random set of other computers obscuring the origin and destination from prying eyes. You can download the app from www.torproject.org

23. Music Player Daemon – This is a free app and its license status is GPL. It is server-side application for playing music. It is capable and can support gapless playback and filesystem monitoring; as a server. You can download the app from www.mpd.wikia.com.

24. VLC -Media player – This is a free app and its license status is GPLv2 or later. It's a light Media Player sportin

Fonte: 25 Best Linux Apps

8 Helpful Linux System Monitoring Commands

From finding out bottleneck in storage to CPU to memory and network, these commands are a must know for Linux monitoring. 

Thursday, September 05, 2013:  Other than the add-on tools that can help the administrators manage their Linux server performance, we bring to you some built-in commands that can help you with information about system activities. These tools can be used to find possible causes of a performance glitch. The commands mentioned below are some of the most basic commands in system analysis and debugging server issues. Have a look: 


1. top (display Linux tasks )

The top program provides a dynamic real-time view of a running system. It can display system summary information as well as a list of tasks currently being managed by the Linux kernel. The types of system summary information shown and the types, order and size of information displayed for tasks are all user configurable and that configuration can be made persistent across restarts. 

The program provides a limited interactive interface for process manipulation as well as a much more extensive interface for personal configuration -- encompassing every aspect of its operation. And while top is referred to throughout this document, you are free to name the program anything you wish. That new name, possibly an alias, will then be reflected on top's display and used when reading and writing a configuration file.

Common hot keys:

t Displays summary information off and on.
m Displays memory information off and on.
A Sorts the display by top consumers of various system resources. Useful for quick identification of performance-hungry tasks on a system.
f Enters an interactive configuration screen for top. Helpful for setting up top for a specific task.
o Enables you to interactively select the ordering within top.
r Issues renice command.
k Issues kill command.
z Turn on or off color/mono

2. vmstat (Report virtual memory statistics )

vmstat reports information about processes, memory, paging, block IO, traps, disks and cpu activity. The first report produced gives averages since the last reboot. Additional reports give information on a sampling period of length delay. The process and memory reports are instantaneous in either case.



-f switch displays the number of forks since boot. This includes the fork, vfork, and clone system calls, and is equivalent to the total number of tasks created. Each process is represented by one or more tasks, depending on thread usage. This display does not repeat. 
-m displays slabinfo. 
-n switch causes the header to be displayed only once rather than periodically. 
-s displays a table of various event counters and memory statistics. This display does not repeat. 

3. w (Show who is logged on and what they are doing)
w displays information about the users currently on the machine, and their processes. The header shows, in this order, the current time, how long the system has been running, how many users are currently logged on, and the system load averages for the past 1, 5, and 15 minutes. 

The following entries are displayed for each user: login name, the tty name, the remote host, login time, idle time, JCPU, PCPU, and the command line of their current process. 

The JCPU time is the time used by all processes attached to the tty. It does not include past background jobs, but does include currently running background jobs.

-h Don't print the header. 
-u Ignores the username while figuring out the current process and cpu times. To demonstrate this, do a "su" and do a "w" and a "w -u".
-s Use the short format. Don't print the login time, JCPU or PCPU times. 
-f Toggle printing the from (remote hostname) field. The default as released is for the from field to not be printed, although your system administrator or distribution maintainer may have compiled a version in which the from field is shown by default. 
-V Display version information. 
-o Old style output. Prints blank space for idle times less than one minute. 
user Show information about the specified user only. 

4. uptime (Tell How Long The System Has Been Running)

uptime gives a one line display of the following information. The current time, how long the system has been running, how many users are currently logged on, and the system load averages for the past 1, 5, and 15 minutes.



5. ps (Report a snapshot of the current processes. )

ps command will report a snapshot of the current processes. To select all processes use the -A or -e option.

To see every process on the system using standard syntax: 
$ ps -e 
$ ps -ef 
$ ps -eF 
$ ps -ely 

To see every process on the system using BSD syntax: 
$ ps ax 
$ ps axu 

To print a process tree: 
$ ps -ejH 
$ ps axjf 

To get info about threads: 
$ ps -eLf 
$ ps axms 

To get security info: 
$ ps -eo euser,ruser,suser,fuser,f,comm,label 
$ ps axZ 
$ ps -eM 

To see every process running as root (real & effective ID) in user format: 
$ ps -U root -u root u 

To see every process with a user-defined format: 
$ ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm 
$ ps axo stat,euid,ruid,tty,tpgid,sess,pgrp,ppid,pid,pcpu,comm 
$ ps -eopid,tt,user,fname,tmout,f,wchan 

Find Out The Top 10 Memory Consuming Process
$ ps -auxf | sort -nr -k 4 | head -10
Find Out top 10 CPU Consuming Process
$ ps -auxf | sort -nr -k 3 | head -10

6. free - (Display amount of free and used memory in the system )

free displays the total amount of free and used physical and swap memory in the system, as well as the buffers used by the kernel. The shared memory column should be ignored; it is obsolete. 



-b Display the amount of memory in bytes. 
-c count Display the result count times. Requires the -s option. 
-g Display the amount of memory in gigabytes. 
-k Display the amount of memory in kilobytes. This is the default. 
-l Show detailed low and high memory statistics. 
-m Display the amount of memory in megabytes. 
-o Display the output in old format, the only difference being this option will disable the display of the "buffer adjusted" line. 
-s Continuously display the result delay seconds apart. You may actually specify any floating point number for delay, usleep(3) is used for microsecond resolution delay times. 
-t Display a line showing the column totals. 
-V Display version information. 

7. mpstat (Report processors related statistics.
)

The mpstat command writes to standard output activities for each available processor, processor 0 being the first one. Global average activities among all processors are also reported. The mpstat command can be used both on SMP and UP machines, but in the latter, only global average activities will be printed. If no activity has been selected, then the default report is the CPU utilization report.
Use mpstat -P ALL to display average CPU utilization per processor.



8. iostat (Report Central Processing Unit (CPU) statistics and input/out‐put statistics for devices and partitions.)

The iostat command is used for monitoring system input/output device
loading by observing the time the devices are active in relation to
their average transfer rates. The iostat command generates reports that
can be used to change system configuration to better balance the
input/output load between physical disks.

 

Atithya Amaresh, EFYTIMES News Network 

Fonte: 8 Helpful Linux System Monitoring Commands

7 Little Command Line Errors That Can Cause Big Disasters

If your system suddenly shut down while you were working on the command line, chances are that you have committed some error. Here we bring to you 7 very silly errors that can cause trouble to you PC.

Wednesday, September 04, 2013:  It is a well known fact that if used incorrectly, even the most powerful too can turn against you, leading to unimaginable losses. Same is the case with the Linus terminal. Even small carelessness with the commands can lead to big system malfunctions which can spell disasters.




Here we bring to you 7 silly command line errors that can create serious havoc in you system.

Warning: DO NOT attempt these command on you system and just in case you willing to try out, you can do that on a virtual machine.

1. Writing rm / somedir instead of rm /somedir

The minor mistake of adding a space in the rm command can actually delete the entire content of the root (/) directory. To avoid such situation, it is advisable to use rm command with the -i extension that prompts before removal. The -i extension is much more helpful as there is no option like undelete in Linux, so whenever you are using the rm command always use the -i extention.

2. -v is not always verbose.

Yes -v is means verbose in most cases of UNIX, but not always! Especially when it comes to pkill. The pkill command that is used to terminate a process with a certain name or pattern. If used with the -v option (which is used to negate the matching), it can kill any process that can be killed except for those whose name contain the process name. This can end up shutting down whole of your system.

3. Writing last | reboot instead of last | grep reboot

Missing the grep in the above command can cause your whole the system to shutdown instead of reboot. So it is advisable to be sure about what you are trying to do with your command. You can always refer the manual page to know about all the features of a command.

4. Writing crontab -r instead of crontab -e

r and e are adjacent to each other in the keyboard, so there are quite some chances that you might make a typo error and use the r instead of e and remove the whole processes instead of editing it. 

Writing /sbin/init 1 instead of /sbin/init q 

Similarly typo error of 1 and q here can cause the system to shutdown.

Hence it is advisable to be precise while typing your commands.

5. Writing g++ -o abc.cpp abc.cpp instead of g++ -o abc abc.cpp

The addition of extension while compiling a c++ file will cause the output of the compiled c++ program to be placed in abc.cpp. As a result, the source code gets deleted. Hence, always keep a backup of your source code.

6. mv /* ../ instead of mv ./* ../

This command which is basically used to move the files in the current directory up one folder to its parent directory. And this little error can move everything from the root directory to the parent directory of the current directory. Which can cause you rescue your grub by reinstalling the OS again.

../ is used to signify the parent directory of the current directory.

./ is used to signify the current directory

/ signifies the root directory

7. Using cat > [filename] instead of cat >> [filename]

‘>>’ is used for appending the content to a file where as ‘>’ is used to overwrite the current content. So, if you replace ’>>’ with ‘>’ the entire content of the file gets deleted.

Courtesy: fortystones 

Atithya Amaresh, EFYTIMES News Network 

7 Little Command Line Errors That Can Cause Big Disasters