AWK Tutorial, Learn AWK
The awk utility interprets a programming language that makes it possible to handle simple data-reformatting jobs easily with just a few lines of code.
SED Tutorial
* The sed utility is an "editor"
* It is also noninteractive. This means you have to insert commands to be executed on the data at the command line or in a script to be processed.
* sed accepts a series of commands and executes them on a file (or set of files).
* sed fittingly stands for stream editor.
* It can be used to change all occurrences of "SAD" to "SED" or "New York" to "Newport."
* The stream editor is ideally suited to performing repetitive edits that would take considerable time if done manually.
This tutorial should enable you to install ffmpeg and the auxiliary libraries that will give ffmpeg support for various codecs. It'll then go on to explain the basics of what a video file is, how it's created by ffmpeg and how a media player takes it apart again to display the picture and give you the sound. Next, you'll find out how to influence the way the data is produced. Finally, I'll deal with more advanced topics such as merging several sources and introducing time differentials.
ffmpeg is a versatile video tool used to encode and convert a multitude of video and audio formats. x264 is a library used to encode H264 video and creates excellent looking video usually superior to xvid and other popular codecs. x264 is used by Avidemux, GordianKnot, VLC Player, MEncoder, and Handbrake.
Although ffmpeg and x264 are available in the Ubuntu repositories, you may need to compile from source. For example, the ffmpeg-user mailing list requires that you use the latest ffmpeg svn before asking for help. Since ffmpeg and x264 are updated frequently, you may also like to have the bleeding-edge for encoding videos. Also, ffmpeg in the Ubuntu repository may not support all of the codecs and formats that you may need.
This tutorial was tested on a command-line install of Ubuntu Hardy Heron (8.04) on a Pentium 4 3.0 GHz with 2 GB RAM using ffmpeg and x264 source files retrieved on May 7, 08. It was also tested in a standard Hardy Heron installation in VirtualBox.
Pidgin (earlier Gaim) is a multiple protocol Instant Messenger client which can be used to chat using MSN, Yahoo, AIM and many other protocols. But most people do not know that you can use Pidgin to chat with Google Talk users.
Pidgin supports a protocol called XMPP (Extensible Messaging and Presence Protocol). XMPP is the core protocol of the Jabber protocol and GTalk is also based on the Jabber protocol. So it is quite easy to make Pidgin to work with GTalk.
rcconf is Debian runlevel configuration tool. Rcconf allows you to control which services are started when the system boots up or reboots. It displays a menu of all the services which could be started at boot. The ones that are configured to do so are marked and you can toggle individual services on and off. If rcconf is not installed use apt-get command:
# apt-get install rcconfOR$ sudo apt-get install rcconf Now run rcconf and just follow on screen instructions:
# rcconf
Optimize what you need to (and only what you need to), profile find out what that is (it may be slow, but profiling is your friend), and use the right tools (rewriting a bit of code with RubyInline is way better than rewriting the whole app in C).
The top two concerns are usually performance and scalability: "Ruby is slow" or "Interpreted languages are slow" seem to be the most common. Here are some excellent articles on the subject (the overall summary being: Rails provides a great advantage in getting your product to market, there are reasonable and inexpensive ways of addressing any performance bottlenecks, and scalability is not a problem):
the cost per request is plummeting, but the cost of programming is not. Thus, we have to find ways to trade efficiency in the runtime for efficiency in the “thought time” in order to make the development of applications cheaper. I believed we’ve long since entered an age where simplicity of development and maintenance is where the real value lies.
You should refer to ITU-T H.264 standard
From the document
Baseline profile: profile_id 66 = 0x42
Main profile: profile_id 77 = 0x4D
Extended profile: profile_id 88 = 0x58
Now that djbdns is public domain it can be included in Debian-based distributions. Gerrit Pape has done the hard work of packaging everything up and submitting to the ftpmasters at Debian, and it looks to have been accepted into sid.
I, however, run Ubuntu, which hasn't imported this package yet. Ideally, I'd also like to avoid running daemontools, as upstart does a similar job and already comes with Ubuntu.
IP Address Locator Tool
This IP Address Map lookup service is provided for FREE by Geobytes, inc to assist you in locating the geographical location of an IP Address. Click here to checkout our other FREE localization services.
If you ssh into a server a lot, you'll get tired of typing in your
password over and over again pretty quickly. Fortunately, you can
generate a set of public and private keys on your local client machine,
place the public key on the server, and ssh without having to enter a
password. Here's how.
Device Manager does not display devices that are not connected to the Windows XP-based computer
View products that this article applies to.
Article ID : 315539
Last Review : November 18, 2005
Revision : 1.2
This article was previously published under Q315539
SYMPTOMS
Device Manager displays only non-Plug and Play devices, drivers, and printers when you click Show hidden devices on the View menu. Devices that you install that are not connected to the computer (such as a Universal Serial Bus [USB] device or "ghosted" devices) are not displayed in Device Manager, even when you click Show hidden devices.
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WORKAROUND
To work around this behavior and display devices when you click Show hidden devices:
1. Click Start, point to All Programs, point to Accessories, and then click Command Prompt.
2. At a command prompt, type the following command , and then press ENTER:
set devmgr_show_nonpresent_devices=1
3. Type the following command a command prompt, and then press ENTER:
start devmgmt.msc
4. Troubleshoot the devices and drivers in Device Manager.
NOTE: Click Show hidden devices on the View menu in Device Managers before you can see devices that are not connected to the computer.
5. When you finish troubleshooting, close Device Manager.
6. Type exit at the command prompt.
Note that when you close the command prompt window, Window clears the devmgr_show_nonpresent_devices=1 variable that you set in step 2 and prevents ghosted devices from being displayed when you click Show hidden devices.
If you are a developer or power user and you want to be able to view devices that are not connected to your computer, set this environment variable globally:
1. Right-click My Computer.
2. Click Properties.
3. Click the Advanced tab.
4. Click the Environment Variables tab.
5. Set the variables in the System Variables box.
NOTE: Use this method only for troubleshooting or development purposes, or to prevent users from accidentally uninstalling a required device that is not connected to the computer (such as a USB device or docking station that is not connected to a laptop computer).
If your Windows XP takes a very long time to shut down, you can try User Profile Hive Cleanup Service provided by Microsoft (yes, Microsoft). The users at digg claimed that it really helps to shorten shut down time. I remember it took a very long time to shut down before I formatted and reinstall my PC not too long ago.
