Category: Linux

Link: BASH Frequently Asked Questions

Here is something we could have used a few times in the past, had we known it existed:

These are answers to frequently asked questions on channel on the freenode IRC network. These answers are contributed by the regular members of the channel (originally heiner, and then others including greycat and r00t), and by users like you. If you find something inaccurate or simply misspelled, please feel free to correct it!

All the information here is presented without any warranty or guarantee of accuracy. Use it at your own risk. When in doubt, please consult the man pages or the GNU info pages as the authoritative references.

BASH is a BourneShell compatible shell, which adds many new features to its ancestor. Most of them are available in the KornShell, too. The answers given in this FAQ may be slanted toward Bash, or they may be slanted toward the lowest common denominator Bourne shell, depending on who wrote the answer. In most cases, an effort is made to provide both a portable (Bourne) and an efficient (Bash, where appropriate) answer. If a question is not strictly shell specific, but rather related to Unix, it may be in the UnixFaq.

This FAQ assumes a certain level of familiarity with basic shell script syntax. If you’re completely new to Bash or to the Bourne family of shells, you may wish to start with the (incomplete) BashGuide.

If you can’t find the answer you’re looking for here, try BashPitfalls. If you want to help, you can add new questions with answers here, or try to answer one of the BashOpenQuestions.

Link: BASH Frequently Asked Questions

Over 100 questions are answered here. And in case you missed it above, this page only shows the questions – you have to click on the links that follow each question to see the answers.

People often don’t realize how powerful BASH really is. Very often people will try to write a program in a higher level language to do a simple task that could easily be done entirely in BASH. Look this page over and you might realize that you can do a lot more with BASH than you thought. And BASH is available in every version of Linux we’ve ever encountered (note we did not say “installed by default”, though it often is nowadays). Even small computers such as Raspberry Pis will usually have BASH installed as part of the operating system.

Links: How to extend the life of the SD card on a Raspberry Pi (or similar device)

People are using the Raspberry Pi for many applications these days, including as a VoIP PBX server based on Asterisk. One thing that many people forget is that you can only write to an SD card a limited number of times before it fails. Asterisk in particular likes to write a LOT of information to log files, and let’s face it, if you are honest and you are like 99% of Asterisk system administrators, you will admit you never read them unless perhaps you suspect there is a problem with your system. Yet every one of those many writes reduces your SD card’s lifespan by a small amount.

So with that in mind, here are links to a few threads that may or may not be helpful, in no particular order:

How can I extend the life of my SD card? (Raspberry Pi Stack Exchange)
How can I use a USB HDD to extend the life of my SD Card? (Raspberry Pi Stack Exchange)
Read/Write cycles of a SD card (RaspberryPi.org)
Extending the life of the SD card (RasPBX – Asterisk for Raspberry Pi/Sourceforge)
How to add ‘noatime’ to fstab? (AYK solutions)

Know of any other good links on the subject? Please leave a comment!

Link: How to remove Zeitgeist in Ubuntu and why

Quoting from the article:

On my desktop I use Xubuntu 12.04, and today i noticed that this distribution shipped by default the Zeitgeist daemon, a thing that I’m not using at all, for what i know.

From Wikipedia:

Zeitgeist is a service which logs the users’s activities and events, anywhere from files opened to websites visited and conversations. It makes this information readily available for other applications to use in form of timelines and statistics. It is able to establish relationships between items based on similarity and usage patterns by applying data association algorithms such as “Winepi” and “A Priori”

Zeitgeist is the main engine and logic behind GNOME Activity Journal which is currently seen to become one of the main means of viewing and managing activities in GNOME version 3.0

Personally i don’t use any tool that use the Zeitgeist Framework and I’d prefer to open a terminal and use locate or find to search for files than having something that log all my activity and so slow down my system, so I’ve decided to remove this daemon totally from my system, please note that if you use Gnome 3 or Unity you could have some side effect, or perhaps the system will just become more faster, like the author of the article: Removing Zeitgeist Sped Up Unity .

Just remember that the information collected by Zeitgeist are stored for use in various forms in Unity: showing what were the last application you used, what are the applications you use most, which are the files that were used lately, the music you listen, among many other aspects. If you think you can live without these information probably your system will gain a good sped up.

The remainder of the article at Linuxaria gives provides the actual removal instructions.

Cubieboard2 open single board computer ships, Cubietruck model revealed

This comes to us from LinuxGizmos:

The forthcoming Cubietruck will have additional I/O ports
The forthcoming Cubietruck will have additional I/O ports

The Cubieboard open SBC project began shipping a faster Cubieboard2 version of its open source Linux and Android SBC, and revealed prototypes of a new, larger, enhanced Cubietruck model. Like the $59 Cubiboard2, the Cubietruck uses an Allwinner A20 dual-core Cortex-A7 SoC instead of the original’s single-core Allwinner A10, and adds a 2GB RAM option, WiFi, Bluetooth, gigabit Ethernet, VGA, and SPDIF ports.

Read the full article here.

Note that the abbreviation “SBC” in the above-linked article stands for “single board computer”. In our opinion, if the Cubietruck works reliably it could relegate the BeagleBoard Black to also-ran status, and could even give the Raspberry Pi a run for its money among those who’d like just a bit more power and a wider selection of outputs. For Home Theater PC builders, the inclusion of a SPDIF Toslink optical port is no small thing. We’ll definitely be keeping an eye on this one!

Link: How to watch Netflix (Watch Instantly) in Linux

EDIT: After publishing this article we learned of another article that gives additional information on what is probably the easiest method so far:

Yesterday, developer and programmer extraordinaire Erich Hoover and I spent several hours working out all of the Netflix Desktop kinks. Most users will have no problems with installation now.

Here is how to install the Netflix Desktop App on Ubuntu. …

Full details here:
PPA for Netflix Desktop App (iheartubuntu)

Should you have problems getting it to work, see:
Report Netflix App Bugs on Launchpad (iheartubuntu)

What follows is the original text of this post, which also mentions this method as one of the two choices:

Running Netflix is entirely possible in Ubuntu Linux 12.04 (and most likely any other modern distribution). See the section below “Running with Wine”.

Until recently there was no simple solution to watching streaming movies via Netflix (Watch Instantly) in Linux for any Linux distros besides Android based computers. Netflix has not released a player that will install natively in any of the others.

Read the full article here:
How to watch Netflix (Watch Instantly) in Linux (How To Wiki)

Useful SSH How-Tos

These are from an interesting site called Make Tech Easier, listed in order from oldest to newest:

Link: MythTV: Use All Buttons of Your Remote Control – Without LIRC

It can be really frustrating to get a remote control to work properly under Linux with LIRC and programs like MythTV, mplayer or XMBC. This article shows how to avoid using LIRC altogether: Treat the remote like any other keyboard, then change the keyboard mapping to use the application’s key shortcuts. Because we do this before the keypresses reach X11, it avoids the dreaded problem of keys with codes >255 not working.

Full article here:
Link: MythTV: Use All Buttons of Your Remote Control – Without LIRC (Richard Atterer)

Link: Sikuli (Automation Tool Using Images) 1.0.0 Released

Sikuli is a tool available for Linux, Windows and Mac OS X which automates tasks using images: you take a screenshot of what you want to click, right click, hover, drag and drop and so on and Sikuli performs those actions automatically, when you need it, either by using the GUI or running it via command line.

It can be useful for running repetitive tasks automatically, running some actions remotely via the command line and so on.

Article continues here:
Sikuli (Automation Tool Using Images) 1.0.0 Released (WebUpd8)

Link and Video: Drastically Speed up your Linux System with Preload (and other speed-ups)

Preload is an “adaptive readahead daemon” that runs in the background of your system, and observes what programs you use most often, caching them in order to speed up application load time. By using Preload, you can put unused RAM to good work, and improve the overall performance of your desktop system.

Most Linux users should install Preload using their distribution’s Software Center or repository, and simply installing the program will be all that is needed.  But this article explains much more about Preload, including various configuration options:

Drastically Speed up your Linux System with Preload (TechThrob)

Preload is also featured in this video:
View on YouTube