Thursday, July 19, 2012

How to run multiple commands in the terminal

Sometimes you may want to run multiple commands in the terminal. Here is how to do it:

If you want to run multiple commands in the terminal respectively, just add a semicolon (;) between two commands. For example:

command1; command2; command3

With this syntax, it does not matter if a command returns to error, all the commands you use will be executed eventually.

If you want to run multiple commands in the condition that the previous command must complete successfully first before running the next command ( in other word, if the first command returns to error, the next commands wont be executed), 2 and symbols (&&) will be used in lieu of the semicolon. For example:
command1 && command2 && command3

If you want to run multiple commands in the condition that the next command will be executed if the previous one fails ( if the first command runs successfully, the next commands wont be run), the syntax will be:
command1 || command2 || command3

Add Round Corners to Your Images the Easy Way with RoundPic

Are you looking for an easy way to add rounded corners to your images without installing extra software? Then you should take a look at RoundPic. The website lets you add rounded corners to images in moments with an easy to navigate interface.
The interface for RoundPic is simple and straightforward. You can choose to upload an image from your computer or enter the URL of an image on the web. Once you have done that click on the Round it! Button.
Here are the default settings that RoundPic will apply to your images. You can make changes and/or adjustments as desired then see the changes by clicking on the Round! Button to apply them. Once you have everything tweaked to your liking simply click the Download Button to download the modified image to your computer.
RoundPic Homepage [via Guiding Tech]

Top 10 Ubuntu App Downloads for June 2012

Canonical published yesterday, July 18th, this month's top 10 app downloads from Ubuntu Software Center. As you can see below, the most appreciated apps are the games from the Humble Indie Bundle V. Without further ado here they are!

Top 10 paid apps:

2. Bastion
3. Amnesia: The Dark Descent
4. Braid
5. Oil Rush
6. Fluendo DVD Player
7. The Journey Down: Chapter One
8. Psychonauts
9. LibreOffice 3.4 Getting Started
10. Superbrothers: Sword & Sworcery EP

Top 10 free apps:

1. Command & Conquer Tiberium Alliances
2. Lord of Ultima
3. Plex Media Server
4. Ryzom
5. CrossOver (Trial)
6. ScreenCloud
7. IntelliJ IDEA Community Edition
8. Full Circle Magazine #59
9. Fetchnotes
10. Vendetta Online

Congrats to the developers of these apps! See you next month for another iteration of Ubuntu Top 10 Apps.

Raspbian: Debian for Raspberry Pi

The Raspberry Foundation managed to deliver their own Linux distribution for the Raspberry Pi hardware, called Raspbian, based on Debian.

Until now, the developers of Raspberry Pi have recommended a Debian Squeeze distribution for their platform, which worked great, but now they have built their own distro that seems to work really great.

Raspbian “Wheezy” is the first Linux distribution to take advantage of the Raspberry Pi’s floating point hardware for, amongst other things, much faster web browsing. At least this is what the developers are saying.

Raspberry Pi relies on an ARM processor with a clock speed of 700 MHz, 256 MB of RAM, an SD card slot and a 5V Micro USB connector that supplies the power. It also features RCA and HDMI ports.

Download Raspbian 2012-07-15

Android for PC Reaches Version 4.0 RC2

Android-x86, the famous port of Google's Android platform for the x86 (32-bit) architecture has just reached version 4.0 RC2.

Android-x86 is a Live CD Linux distribution created mostly for the Eee PC netbooks, but can also run on any other 32-bit (x86) platform.

Highlights of Android-x86 4.0 RC2:

• Linux kernel 3.0.36 has been implemented, bringing more drivers and bug-fixes;
• Dalvik JIT compiler support has been enabled;
• Some 3G modems are now supported;
• Arm translator can now be used, but it still needs Intel's libraries from BuilDroid;
• Physical keyboard layout selection implemented;
• Added support for two cameras;
• Fake SD card has been replaced by internal storage support.

More details about the release can be found in the official announcement.

 Download Android-x86 4.0 RC2

HTG Explains: What Runlevels Are on Linux and How to Use Them

When a Linux system boots, it enters its default runlevel and runs the startup scripts associated with that runlevel. You can also switch between runlevels – for example, there’s a runlevel designed for recovery and maintenance operations.
Traditionally, Linux used System V-style init scripts – while new init systems will eventually obsolete traditional runlevels, they haven’t yet. For example, Ubuntu’s Upstart system still uses traditional System V-style scripts.

What’s a Runlevel?

When a Linux system boots, it launches the init processes. init is responsible for launching the other processes on the system. For example, when you start your Linux computer, the kernel starts init, and init executes the startup scripts to initialize your hardware, bring up networking, start your graphical desktop.
However, there isn’t just one single set of startup scripts init executes. There are multiple run levels with their own startup scripts – for example, one runlevel may bring up networking and launch the graphical desktop, while another runlevel may leave networking disabled and skip the graphical desktop. This means you can drop from “graphical desktop mode” to “text console mode without networking” with a single command, without manually starting and stopping different services.
More specifically, init runs the scripts located in a specific directory that corresponds to the runlevel. For example, when you enter runlevel 3 on Ubuntu, init runs the scripts located in the /etc/rc3.d directory.
At least, this is how it works with a traditional System V init system – Linux distributions are beginning to replace the old System V init system. While Ubuntu’s Upstart currently maintains compatibility with SysV init scripts, this is likely to change in the future.

The Runlevels

Some runlevels are standard between Linux distributions, while some runlevels vary from distribution to distribution.
The following runlevels are standard:
  • 0 – Halt (Shuts down the system.)
  • 1 – Single User Mode (The system boots into superuser mode without starting daemons or networking. Ideal for booting into a recovery or diagnostics environment.)
  • 6 – Reboot
Runlevels 2-5 vary depending on distribution. For example, on Ubuntu and Debian, runlevels 2-5 are the same and provide a full multi-user mode with networking and graphical login. On Fedora and Red Hat, runlevel 2 provides multi-user mode without networking (console login only), runlevel 3 provides multi-user mode with networking (console login only), runlevel 4 is unused, and runlevel 5 provides multi-user mode with networking and graphical login.

Switching to a Different Runlevel

To switch to a different runlevel while the system is already running, use the following command:
sudo telinit #
Replace # with the number of the runlevel you want to switch to. Omit sudo and run the command as root if you’re running a distribution that doesn’t use sudo.

Booting Directly to a Specific Runlevel

You can select a runlevel to boot into from the boot loader – Grub, for example. At the start of the boot process, press a key to access Grub, select your boot entry, and press e to edit it.
You can add single to the end of the linux line to enter the single-user runlevel (runlevel 1). (Press Ctrl+x to boot after.) This is the same as the recovery mode option in Grub.
Traditionally, you could specify a number as a kernel parameter and you’d boot to that runlevel – for example, using 3 instead of single to boot to runlevel 3. However, this doesn’t appear to work on the latest versions of Ubuntu – Upstart doesn’t seem to allow it. Similarly, how you change the default runlevel will depend on your distribution.

While Ubuntu’s Upstart daemon still emulates the SystemV init system, much of this information will change in the future. For example, Upstart is event-based – it can stop and start services when events occur (for example, a service could start when a hardware device is connected to the system and stop when the device is removed.) Fedora also has its own successor to init, systemd.

Dell XPS 13 Laptop Will Come with Ubuntu 12.04

After announcing a collaboration with Canonical to sell laptops in 850 retail outlets across India, starting this Saturday, July 21st, Dell comes now with another major announcement related to Project Sputnik.

Remember Project Sputnik? Officially announced as an experiment in May this year, Project Sputnik was supposed to be an open source laptop targeted for developers, which will run Ubuntu 12.04 LTS.

Well, guess what?! Yesterday, July 18th, Dell proudly announced in a press release that Project Sputnik will become reality this fall, which will result in a developer laptop based on Dell XPS 13, pre-loaded with the Ubuntu 12.04 LTS (Precise Pangolin) operating system.

Available this fall in selected regions, the Dell XPS 13 laptop will offer a complete client-to-cloud solution to all Linux developers, with software to build "microclouds" on their netbooks, in order to simulate an at-scale environment that can be seamlessly deployed to the cloud.

 "This project represents the first of many new ideas Dell employees will test with customers or partners through the program, and we look forward to supporting Sputnik to be successful as it becomes a product this fall," said Nnamdi Orakwue, executive sponsor of the Dell incubation program and executive assistant to Michael Dell.

"Since we announced project Sputnik a little over two months ago, we have continued to be amazed by the amount and quality of interest and input we have received."

"By listening to developers, Dell can provide them with solutions and products to help make them more productive and allow for greater innovation," said Barton George, project Sputnik lead and director at Dell's web vertical marketing.

In the press release, Dell also announced new technologies and new partners in order to accelerate customer cloud development and value from big data. For more details please check out the official announcement here.

LibreOffice Writer Introduction

If you are looking for a full-featured text editor with nothing left out it may be time to try LibreOffice. This fantastic set of software will allow you to create mesmerizing documents with stylish text formatting, images, tables, calculations, and much more.
But first its time to look specifically at LibreOffice writer, and all the available features. Here you will see all the options and functions available to create powerful text documents with a professional desktop publishing look.

Rest here

Ubuntu 12.10 Will Offer a Revamped Nautilus

With today's updates, Canonical made some changes to the upcoming Ubuntu 12.10 (Quantal Quetzal) operating system, regarding the GNOME packages, especially Nautilus.

After revamping the Session Indicator last week and the ability to sort time zones in the Date and Time Indicator, the Ubuntu developers updated the GNOME packages in the upcoming Ubuntu 12.10 operating system to version 3.5.4, which we'll announce later this week.

More exactly, the GNOME 3.5.4 development release comes with a revamped Nautilus, which is now available in the daily build version of Ubuntu 12.10.

As you can see from the screenshot above, the revamped Nautilus comes with a completely remodeled toolbar layout, new sidebar icons, new search function, and the app menu was moved into a button on the toolbar.

It also comes with features like Copy To and Move To actions, notification when ejecting volumes, various tweaks to the list view, and lots of other small improvements and fixes.

Ubuntu One Files Java Library Released

Today, July 18th, Canonical posted on the Ubuntu One blog, that they've just released a Java library that will allow access to files stored on your personal Ubuntu One cloud storage account.

This means that by using this Java library any developer can now build applications that will have built-in support for the Ubuntu One cloud storage, allowing users to access their files.

"You can bundle it with the Ubuntu SSO Java library and harness Ubuntu One cloud storage in your apps. The Ubuntu One Files Java library allows you to talk to the Ubuntu One REST API from Java."

The Ubuntu One Java library has no Android dependencies, which means that it's suitable for use in applications built with Java SE 1.6 runtime, as well as Android apps.

For detailed documentation about the Ubuntu One Java library, how to download it, implemented it, etc. you can check out the official blog announcement.

Scientific Linux 6.3 Beta 1

Pat Riehecky has announced the availability of the first beta version of Scientific Linux 6.3, a distribution built from source packages of Red Hat Enterprise Linux and enhanced with extra applications useful in academic environments: "There should be no expectation that a 'yum' upgrade to SL 6.3 will work. A new install is the recommended method to move from 'sl6rolling'(this alpha release) and the released 'SL 6.3'. Major changes made: LibreOffice - has been replaced with LibreOffice. The LibreOffice packages 'provide' the right packages to maintain compatibility for Kickstart and yum installs; Anaconda - Anaconda now alerts users to the beta status of a release when it is tagged appropriately, upstream has added this functionality and we are taking advantage of it for the beta cycle...." Read the full release announcement. Download the DVD images: SL-6.3-i386-DVD.iso (3,464MB, SHA), SL-6.3-x86_64-DVD.iso (4,093MB, SHA256).

Zentyal 2.3-2

José Antonio Calvo today announced a beta release of Zentyal 2.3, a small business server for managing various network services: "We are glad to let you know that Zentyal has already entered the feature freeze period for 3.0, meaning that from now on we will be focused on polishing and bugfixing until September. Some of the highlights included in this new version are: first version of the brand new HTTP proxy module, with a much simpler interface and improvements like now it is possible to apply different filter profiles on different time periods; new features on Samba4, allowing to set administrator account or edit general settings without having to disable the module; several improvements in Firewall, OpenVPN and Captive Portal modules, featuring support for SNAT rules, MAC filtering and Captive Portal objects and services exceptions...." Follow the full release announcement. Download: zentyal-2.3-2-i386.iso (614MB, MD5), zentyal-2.3-2-amd64.iso (625MB, MD5).