Geek Stuffs

Replacing OpenDNS with Google Public DNS

2009-12-16T17:38:00.005+05:30

I have been using OpenDNS to browse faster, safer, and fix DNS errors. But now Google Public DNS is a new challenger which is encourging web users to use their settings on Networks to speed up your browsing experience and get improved security.

Google Public DNS is a free, global Domain Name System (DNS) resolution service, that you can use as an alternative to your current DNS provider. Since a faster and safer DNS infrastructure could significantly improve the web browsing experience, Google Public DNS promises to do just that.

Get started with Google Public DNS
Read the configuration instructions and then configure your network settings to use the IP addresses 8.8.8.8 and 8.8.4.4 as your DNS servers. Remember after that your client programs will perform all DNS lookups using Google Public DNS. For once .. no Google account needed.

Quick Start on Windows Vista
Go the Control Panel > Click Network and Internet > Network and Sharing Center > Manage network connections > Right-click Local Area Connection / Wireless Network Connection > Click Properties > Select Networking tab > Click Internet Protocol Version 4 (TCP/IPv4) > Click Properties > Replace Preferred DNS server and Alternate DNS server with Google DNS servers: 8.8.8.8 and 8.8.4.4 > OK.

So which is better – OpenDNS or Google Public DNS? Both are really good and only time will tell. The best part is that short Google IP addresses are really much easier to remember than OpenDNS. I switched and its working lightening fast as of now. Another ace by Google to speed up the web. And if you are still using the DNS settings of your ISP, try out these DNS services and feel the difference … and secure your browsing.

Microsoft Products Error Messages & Solutions

2009-12-07T15:45:00.004+05:30

Its common to encounter error messages while using Microsoft products for any IT professional. Error messages arise due to the virus attacks, system malfunction, malware or adware attacks, files overwrite problem and through many other resources. Well good news is this, you do not have to go and search for every error message that you encounter with Windows, Microsoft Office or any other product. It is now all at the single place.

Microsoft has organized their help and support system. Microsoft has introduced an online automated troubleshooting system. It is very good approach of Microsoft to organize and provide the solution to every error message of Microsoft products at single place. To use this automated help and support system, just go to the below mentioned Microsoft URL and type in the error message or error code which you are encountering. The results will start appearing below immediately. Select required result and it will tell you the exact solution for your problem.

Visit Microsoft Help and Supported Automated System.

Useful Websites 2

2009-11-19T16:18:00.005+05:30

Links

http://katz.cd/
http://www.phazeddl.com/

Downloads

http://www.download.com/
http://www.softpedia.com/
http://www.soft32.com/
http://www.soft82.com/
http://3d2f.com/
http://www.filehippo.com/

Forums (Softwares)

http://crackedsoftwares.com/
http://www.warezteam.com/
http://www.freesoft.in/
http://www.final4ever.com/
http://www.exbii.com/
http://www.downforum.com/
http://warezraid.com/
http://waz-warez.org/
http://bayw.org/
http://crostuff.net/
http://warezboard.net/
http://www.zeedownload.org/
http://balkanw.org/
http://www.warezskill.org/
http://warezraid.com/
http://www.pirateflames.com/
http://platinumw.org/
http://thephoenix-forums.com/
http://war3zunlimit3d.com/
http://xsaimex.net/
http://swtim.org/
http://thedownloadforum.com/
http://neosharez.com/
http://watchingducks.info/
http://nd-warez.info/
http://latestwarez.com/
http://alb-share.com/
http://realdl.com/
http://dreamforums.org/
http://warez-central.net/
http://linkzshare.net/
http://da-legends.info/
http://dirtydingo.org/
http://theseekersoasis.org/
http://zipile.com/
http://hackerz-bb.info/
http://rapidsharegarden.com/
http://warezwebmasters.co.uk/
http://symbiansector.net/
http://elitepirate.com/
http://joeschatterbox.co.uk/
http://gurudl.com/
http://kj9s.com/
http://apps.katz.cd/site/warezscene.org
http://legendaryhackerz.com/
http://hitzwarez.com/
http://wareztalkz.com/
http://phrozenfilez.com/
http://warez-bay.com/
http://theseekersoasis.org/
http://lineapps.com/
http://codehacks.org/
http://triniwarez.com/
http://hitzwarez.com/
http://bookviet4a.org/
http://ctforumgroup.com/
http://forumcraze.com/
http://owlsnest.info/
http://5starsbazaar.net/
http://xtremew.org/
http://owlsnest.info/
http://badboys-aftermath.com/
http://tachoz.net/
http://phrozenfilez.com/
http://warezusa.org/
http://mybluemoon-planet.com/
http:/vs-zone.org
http://fast-blog.org/
http://warez.4biz.com.ua/
http://apnigang.com/
http://rapidw.org/
http://quickmovies.org/
http://balkanw.org/
http://da-legends.info/
http://site/pengushare.com
http://site/swtim.org
http://site/novawarez.org
http://xsaimex.net/
http://flaminbox.com/
http://warezdominator.com/

Movies

http://neverlegit.org/
http://crostuff.net/
http://onlineflixz.com/
http://bootforfun.com/
http://watchingducks.info/
http://bestleech.com/
http://forum.poizonx.com/
http://aiostop.com/
http://megashareslink.com/
http://w4rez.org/
http://flaminbox.com/
http://neverlegit.org/
http://flaminbox.com/

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Chace to get Winspy for free

2009-11-18T13:01:00.002+05:30

Hi friends, We have a great chance to win Winspy for free. All you have to do is participate on the contest.

The Features of Winspy Keylogger:

Monitor Chat Room (dual side) and Web Activity
Monitor any Email
Monitor Children’s activities on Computer / Web
Monitor Employees or counter monitor employers
Monitor a cheating spouse
Records any password
Monitors across networks
Monitor by user
Monitor via Webcam (record/view)
Monitor via Mic (record/view)
Monitor multiple remote PC
Remote Deployment and Monitoring
Remote FTP (upload/download) any file to remote PC
Password Protected and special Hot Key for program
Monitor in Total Stealth
Monitor Remote PC Webcam

So why are you waiting. Just go ahead and participate in the contest.

Contest

Home Page

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Waving Happily

2009-11-09T17:42:00.005+05:30

Today i received Invitation from Danijel Maricicto to preview Google Wave. I have been waiting for this for a month. Atlast i get an invitation from Danijel. Thanks a lot to him..

Here is my invitation..

And my Wave Home is

Onething i know first is Google Wave is entirely different from Emails. But new Wavers does not have invitations. This is really disappointing among New Wavers. Hope they will rolled out invitations for all Wavers.
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Record Keystrokes of your PC

2009-11-05T19:05:00.008+05:30

Have you ever got the feeling to take your home PC security and privacy to yet further more level? If your PC is used by other family members and/or friends and you want to monitor every log, every keystroke, every click with visual screenshots, complete online history, two way chats and anything happening at your PC used by any user, then here is a secret solution for you.

Superior stealth, secret, invisible keylogger is a very powerful PC and Internet monitoring software, it secretly records absolutely every keystroke entered on your computer, retaining all key information even in the event of an abnormal shutdown. It also records chats from all popular clients. The PRO version incorporates visual surveillance techniques that allow you to set the quality and time period of the screenshots it takes like a surveillance camera. Easy to use and compact - Easy to use and install, it is designed for all levels of users. Low on system requirements, it does not slow your computer down. Monitors Internet activity - An invisible keylogger, it secretly watches Internet activity and logs every web-site visited. You can monitor other PC users activity and act timely if needed to save yourself or others whats not right, using this software.

Features:

Captures AOL/AIM/Yahoo/ICQ/MSN chats. Records two-way chats. Supports also the latest messengers version: (ICQ, MSN live, Yahoo!, AOL/ AIM)
Completely hidden from users; it is invisible in windows NT/2000/XP Task manager and Windows 95/98/ME Task list. It cannot be viewed in registry startup list either, making it a highly effective monitoring solution for your surveillance needs.
Captures all passwords - An advanced stealth keylogger, it secretly captures and logs all passwords, even those behind asterisks, so you can immediately identify who logged into your accounts.
Online chats - Captures all on-line chats on AOL, AIM, MSN, Yahoo and ICQ in the two-way mode, allowing you to take timely action to protect your family and business interests.
Supports all Keyboards - Unlike other keyloggers, this USB Keystroke Recorder supports all international keyboards including a USB keyboard, precluding the need for a separate adapter set for USB operation.
Enables log viewing by simple press of the button.
Auto-run at startup - no need for a manual launch.
Monitors all users of the PC - even if you don't know their passwords.
User friendly log - It records all applications run and text typed, logging the password, time, date, window caption and the launched program options in an easy to understand format.
The PRO version will also send the log to you by e-mail, no matter where you are, allowing you to easily find, open, save or delete data. The user-friendly log is accessible only to you via a unique username and password that only you can change
Visual surveillance - (PRO version) All you have to do is to click to enable visual surveillance and customize the degree of picture quality and the time period that should elapse between screen shots.
Monitors opened applications and windows - (PRO version) Information for the user, date and time.
Password protected - (PRO version) In the settings dialog you can enter your password, so the program can be started only with this password.
UDP/TCP connections logging.

Download Smart Keystroke recorder Pro

Download

Please share your views on Comments Section.
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SwingVine Keeps A Pulse On What’s Trending On The Web

2009-09-08T13:36:00.005+05:30

There are many sites that try to help consumers keep a pulse on the buzz of what’s happening on the web. StumbleUpon, iLike, and others all try to help users search for and find specific, personalized content on the web that may be appealing to them. SwingVine is trying to serve this purpose by aggregating data and news from across the web, analyzing the volume of online buzz, the reputation of various sources, user interactions on the site itself, and other information to surface the the most popular and noteworthy content on the web. It’s a hybrid of an aggregator of information on pop culture and news and an analytics site that actually measures what people are looking for on the web.

Content on SwingVine spreads over a number of verticals including music, movies, technology, gadgets, fashion and more. When you click on a recent story or album, you will be led to a page that includes a detailed description of the subject, related media, video and images, and a RSS feed of blogs and news sites that have written about the topic. You can also rate and comment on the item, and share your comment on Facebook, Digg or MySpace.

SwingVine is designed to be a discovery search engine for people to not only see what’s buzzing on the web, but also make sense of it. It’s purpose is noble; with so much content emerging on the web, from music to movies to news and tech gadgets, there is a need for a tool to help people know what’s worth reading into.

SwingVine will face the challenge of competing with small yet well-funded niche social search engines like Oneriot and Blekko, that also offer users a way to see the chatter on the web. And of course, Google Trends and Twitter’s trending topics sites like TweetMeme also serve a similar purpose as SwingVine.

Source : Techcrunch

What is svchost.exe And Why Is It Running?

2009-04-09T11:08:00.001+05:30

You are no doubt reading this article because you are wondering why on earth there are nearly a dozen processes running with the name svchost.exe. You can't kill them, and you don't remember starting them… so what are they?

So What Is It?

According to Microsoft: "svchost.exe is a generic host process name for services that run from dynamic-link libraries". Could we have that in english please?

Some time ago, Microsoft started moving all of the functionality from internal Windows services into .dll files instead of .exe files. From a programming perspective this makes more sense for reusability… but the problem is that you can't launch a .dll file directly from Windows, it has to be loaded up from a running executable (.exe). Thus the svchost.exe process was born.

Why Are There So Many svchost.exes Running?

If you've ever taken a look at the Services section in control panel you might notice that there are a Lot of services required by Windows. If every single service ran under a single svchost.exe instance, a failure in one might bring down all of Windows… so they are separated out.

Those services are organized into logical groups, and then a single svchost.exe instance is created for each group. For instance, one svchost.exe instance runs the 3 services related to the firewall. Another svchost.exe instance might run all the services related to the user interface, and so on.

So What Can I Do About It?

You can trim down unneeded services by disabling or stopping the services that don't absolutely need to be running. Additionally, if you are noticing very heavy CPU usage on a single svchost.exe instance you can restart the services running under that instance.

The biggest problem is identifying what services are being run on a particular svchost.exe instance… we'll cover that below.

If you are curious what we're talking about, just open up Task Manager and check the "Show processes from all users" box:

Checking From the Command Line (Vista or XP Pro)

If you want to see what services are being hosted by a particular svchost.exe instance, you can use the tasklist command from the command prompt in order to see the list of services.

tasklist /SVC

The problem with using the command line method is that you don't necessarily know what these cryptic names refer to.

Checking in Task Manager in Vista

You can right-click on a particular svchost.exe process, and then choose the "Go to Service" option.

This will flip over to the Services tab, where the services running under that svchost.exe process will be selected:

The great thing about doing it this way is that you can see the real name under the Description column, so you can choose to disable the service if you don't want it running.

Using Process Explorer in Vista or XP

You can use the excellent Process Explorer utility from Microsoft/Sysinternals to see what services are running as a part of a svchost.exe process.

Hovering your mouse over one of the processes will show you a popup list of all the services:

Or you can double-click on a svchost.exe instance and select the Services tab, where you can choose to stop one of the services if you choose.

Disabling Services

Open up Services from the administrative tools section of Control Panel, or type services.msc into the start menu search or run box.

Find the service in the list that you'd like to disable, and either double-click on it or right-click and choose Properties.

Change the Startup Type to Disabled, and then click the Stop button to immediately stop it.

You could also use the command prompt to disable the service if you choose. In this command "trkwks" is the Service name from the above dialog, but if you go back to the tasklist command at the beginning of this article you'll notice you can find it there as well.

sc config trkwks start= disabled

Hopefully this helps somebody!

Temporarily Disable "Restart Now" Dialog from XP's Automatic Updates

2009-03-25T18:34:00.001+05:30

Automatic Updates is a great feature. Your computer stays protected from threats without worrying about it… but if it's 3am and I'm trying to play a video game, the last thing I want is for the automatic updates to pop up and remind me every 5 minutes that I need to reboot, interrupting my game… Drives me crazy!

Dear Restart Dialog,

I hate you.

If you want to temporarily disable this popup message and delay rebooting, you can go about it one of two ways. I'm a command line junkie, so I just type this into a command prompt (make sure you use the quotes)

net stop "automatic updates"

Or you can open Control Panel \ Administrative Tools \ Services and click Stop on automatic updates.

Do not disable the automatic updates service, just stop it. The next time you start up your computer, it will restart.

Note: If you open the Automatic Updates icon in Control Panel, it will automatically restart the service, which will make the dialog start popping up again.

Troubleshooting "My Computer" Opening Slowly on Windows XP

2009-03-25T18:32:00.001+05:30

If "My Computer" takes a really long time to open on your computer, you are most likely experiencing a well-known issue where Windows hangs while trying to search for network folders and printers before displaying anything to you.

This problem is easily solved, and most of you are probably familiar with the fix already, but we'll go through it anyway.

Open up Folder Options from the Tools menu in Windows Explorer:

Then choose the View tab:

Uncheck the box for "Automatically search for network folders and printers", and close the dialog.

The changes should be immediate, and your problem should be gone.

Clear Recent Commands From the Run Dialog in Windows XP

2009-03-25T18:22:00.000+05:30

Has it ever bothered you that there isn't an obvious way to remove the previous items in the Run box in Windows? It's often very useful, of course… but if you are just a little bit paranoid you might want to clean out that list on occasion.

Of course there are many cleaner applications that will do this for you, but we'll explain how to do it manually.

Clear Recent Run Dialog Entries Through Regedit

Open up regedit.exe through the start menu run box, and then navigate down to the following key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU

You'll see all your recent commands on the right, and you can delete any of the keys that contain your commands. You'll have to logoff and then back on, but the list should be clean.

Note that this will also work for Windows Vista's Run dialog, although most people have switched to using the search box instead.

Completely Clear Recent Run Dialog Entries The Easier Way

Reader Ayush pointed out a much more easy solution that this registry hack-happy geek overlooked.

Right-click on the taskbar and choose Properties, then choose Start Menu.

Select the "Classic Start menu" option, and choose the Customize button. (Don't worry, we'll cancel out of the dialogs so you can keep the XP menu style)

Now just click the Clear button to remove all of the recent documents and applications from the start menu.

Once you've done that, hit Cancel and then Cancel again to make sure you don't switch to the Classic Start menu.

Note that this method will clear out everything… so if you just want to remove a single entry you need to use the registry hack method.

Add Copy To / Move To to the Windows Explorer Right Click Menu

2009-03-25T18:18:00.001+05:30

A hidden functionality in Windows allows you to right click on a file, select Copy To Folder or Move To Folder, and the move to box will pop up and let you choose a location to either copy or move the file or folder to.

Here's the quick registry hack to get this working. As usual, back up your registry just in case. You will want to browse down to this key:

HKEY_CLASSES_ROOT\AllFilesystemObjects\shellex\ContextMenuHandlers

Once you are at that key, right click and choose the New Key option:

Now you will double-click on the (Default) value and enter the following:

{C2FBB630-2971-11D1-A18C-00C04FD75D13}

Click OK and continue.

If you want to enable Move To, you will repeat the same steps, except creating a new key named Move To, and using this value:

{C2FBB631-2971-11D1-A18C-00C04FD75D13}

Now when you right click on a file or folder, you should see the following options:

Let's click Copy To Folder just to see what happens….

And that's it. Useful!

Watch Movies in Your Linux Terminal Window

2009-03-24T18:13:00.002+05:30

In these days of high definition videos everywhere (even YouTube), only the truly geeky would decide to watch their movies in ASCII text in a terminal window. The surprising thing is that some videos are even fairly watchable.

I've found that cartoons work best because of the limited detail. Even more importantly, the series finale and (probably) last ever Futurama movie is coming out Tomorrow on DVD! You can pre-order Futurama: Into the Wild Green Yonder on Amazon.

Watch Movies in ASCII

The first thing you'll want to do is make sure that mplayer is installed, which is easy enough from the command line:

sudo apt-get install mplayer

Then, to actually watch the movies from a terminal window, use the following syntax, replacing MovieName with the filename of your video.

mplayer -vo caca MovieName.avi

The "caca" command is actually the color text driver - you could also use " -vo aa " instead for black & white, but that would just be silly.

These screenshots don't really do it justice - it's seriously just as bad when you're watching.

Sequences with a lot of contrast work better…

And it wouldn't help to sit about 8 feet back from the monitor.

How To Get Detailed Information About Your PC

2009-03-24T17:57:00.002+05:30

Do you want to easily find detailed information about your Windows PC in one easy to use application? There are several system information utilities available and today we will look at three that do a very good job.

SIW – System Information for Windows

You can run run it from a USB stick or use the installer version which is free for personal use. There is also a Business and Technician's version that allow the creation of reports in different formats. SIW looks deep into your system and reports on software, hardware, the OS, and essentially anything else you can imagine.

You can add even more hardware and software categories by going into preferences.

Download SIW (System Information for Windows)

AusLogics System Information

This free utility from AusLogics does a good job of presenting different aspects of your system information in an attractive, easy to use interface. Categories include General Information, Operating System, Devices, Video, Memory Usage, Performance, Hard Drive, Programs, USB devices, and Network.

You can create full detailed reports in HTML, XML, or plain text.

Download AusLogics System Information

Sysinternals Suite

Finally we will look at what is arguably the most comprehensive system info utility…Sysinternals Suite from Mark Russinovich. This suite is a collection of more than 60 individual tools and help files for all aspects of your system. There are far to many great tools in this collection one of which is Autoruns, a great utility to see every single startup item such as applications, explorer add-ons, drivers, services and much more.

Also included in the suite is Desktops 1.0 which is a very neat virtual desktop app that allows up to 4 desktops on one screen, similar to the Linux feature, this comes in very handy in XP and Vista Home edition.

You can choose your hotkey combination to toggle through the different desktops.

Download Sysinternals Suite

Motherboard Fundamentals

2009-03-24T13:47:00.001+05:30

I can say with certainty that almost all the people reading this blog display a degree of knowledge in using a computer. But how many of us have actually opened a computer and tried to figure out and correctly identify the different parts in it ? Not all of us I believe.

So for those who are in the dark, here is a crash course in understanding the architecture of a motherboard. This relatively old article explains the different parts of the motherboard and in what way each part contributes in the overall working of a computer. The article written by Jon Stokes starts from the basics and gradually move into relatively technical jargon such as northbridge and southbridge, the different buses, their protocols and bridges.

Fig: The motherboard layout

While this article is nearly two years old and I am sure, the technology has moved forward a great deal in this time, nevertheless, it gives an insight into what comprises a motherboard in a computer.

Read the article to find out more.

Quick editing ofa command in BASH

2009-03-24T13:36:00.001+05:30

Sometimes when you try to execute a long command, it scrolls beyond the screen. Then if you want to modify the command and re-execute it, there is an easy way for it. Just type "fc" which will load the command in your default editor; in my case vi. Now you can modify the command in the editor and exit the editor, and your modified command is executed automatically.

For example try typing the following command in the bash shell and type "fc".

$ find /etc -iname '*.conf' -exec grep -H 'log' {} \;
$ fc

"fc" will bring the last command typed into an editor, "vi" if that's the default editor. Of course you can specify a different editor by using the -e switch as follows:

$ fc -e emacs

To list last few commands, type:

$ fc -l

For the last 10 commands it will be:

$ fc -l -10

To seach for a command, type "CTRL+r" at the shell prompt for starting a search as you type prompt. Once you found your command, press enter to execute it.

If you want to transpose two characters say you typed 'sl' instead of 'ls'. Then move the cursor between 'sl' and type "CTRL+t".

Make your BASH Scripts user friendly using Dialog

2009-03-24T13:30:00.002+05:30

If you have installed Linuxusing the text installer, then you will find a neat professional looking install process. You can rest assured that no extreme programminghas gone into creating the text installer. In fact, it has been created using a utility called dialog. Dialog is a utility installed by default on all major Linux distros. It is used to create professional looking dialog boxes from within shell scripts.

Some of the dialogs supported are Input boxes, Menu, checklist boxes, yes/no boxes, message boxes, radiolist boxes and text boxes.

Creating a dialog is very easy. Here I will explain how to create dialog boxes of different types.

Input boxes : These allows the user to enter a string. After the user enters the data, it is written to standard error . You may also redirect the output to a file.

$ dialog --title "Ravi's Input Box" 
   --inputbox "Enter the parameters..." 
   8 40

As you can see, the options are self explanatory. The last two options 8 and 40 are the height and width of the box respectively.

Fig: Inputbox

Textbox : This is a box which takes a file as the parameter and shows the file in a scrollable box.

$ dialog --title "textbox" --textbox ./myfile.txt 22 70

... it shows the file myfile.txt in a textbox.

Fig: Textbox showing the file.

Checklist : The user is presented with a list of choices and can toggle each one on or off individually using the space bar.

$ dialog --checklist "Choose your favorite distribution:" 
         10 40 3 
         1 RedHat on 
         2 "Ubuntu Linux" off 
         3 Slackware off

... here, 10 is the height of the box, 40 - width, 3 is the number of choices, and the rest are the choices numbered 1,2 and 3.

Radiolist: It displays a list containing radio buttons. And the user can only choose one option from the set of options.

$ dialog --backtitle "Processor Selection" 
         --radiolist "Select Processor type:" 
         10 40 4 
         1 Pentium off 
         2 Athlon on 
         3 Celeron off 
         4 Cyrix off

10 and 40 are the height and width respectively. 4 denotes the number of items in the list.

Infobox: This is useful for displaying a message while an operation is going on. For example, see the code below:

$ dialog --title "Memory Results" 
         --infobox "`echo ;vmstat;echo ;echo ;free`"
         15 85

Fig: Information box - listing the vmstat and free listing.

Fig: Message box

Dialog is usually used inside a script which gives the script a degree of user friendliness. There is another package called Xdialog which gives the same features for scripts executed in X windows. Xdialog utility also has additional functionality not found in the dialog utility.
To know more about the dialog utility check the man page of dialog.

BASH Completion - Makes life easier for Linux users

2009-03-24T13:23:00.002+05:30

One thing that really makes working in the command line in Linux
a pleasure is the various in-built shortcuts and name completion features in Bash - the default shell in Linux.

But one grouse I always had was it was really difficult to remember all the options that each command had. For example, 'find' came with numerous options which I found difficult to memorize and had to resort to reading the man page each time I had to use the command. Now you can enhance the bash shell to give you the added functionality of listing the options that can be used with a command. For that you should download and install an add-on package called bash-completion. I use Fedora Core 2 but if you are using the latest Linux distribution, it might be installed by default on your machine.
In Debian based Linux distributions, you may install it using the following command :

# apt-get install bash-completion

After installing the bash-completion package, fire up a terminal and type:

$ grep - -

... followed by two TABs and you get all the options that can be passed to the grep command (see figure). This works for any command in linux. Now you don't have to remember all those options that need be passed to the programs any longer.

BASH Shortcuts

2009-03-24T13:12:00.001+05:30

Bash, which is the default shell in Linux contains a whole lot of key bindings which makes it really easy to use . The most commonly used shortcuts are listed below :

____________CTRL Key Bound_____________

Ctrl + a - Jump to the start of the line
Ctrl + b - Move back a char
Ctrl + c - Terminate the command
Ctrl + d - Delete from under the cursor
Ctrl + e - Jump to the end of the line
Ctrl + f - Move forward a char
Ctrl + k - Delete to EOL
Ctrl + l - Clear the screen
Ctrl + r - Search the history backwards
Ctrl + R - Search the history backwards with multi occurrence
Ctrl + u - Delete backward from cursor
Ctrl + xx - Move between EOL and current cursor position
Ctrl + x @ - Show possible hostname completions
Ctrl + z - Suspend/ Stop the command

____________ALT Key Bound___________

Alt + < - Move to the first line in the history
Alt + > - Move to the last line in the history
Alt + ? - Show current completion list
Alt + * - Insert all possible completions
Alt + / - Attempt to complete filename
Alt + . - Yank last argument to previous command
Alt + b - Move backward
Alt + c - Capitalize the word
Alt + d - Delete word
Alt + f - Move forward
Alt + l - Make word lowercase
Alt + n - Search the history forwards non-incremental
Alt + p - Search the history backwards non-incremental
Alt + r - Recall command
Alt + t - Move words around
Alt + u - Make word uppercase
Alt + back-space - Delete backward from cursor

----------------More Special Keybindings-------------------

Here "2T" means Press TAB twice

$ 2T - All available commands(common)
$ (string)2T - All available commands starting with (string)
$ /2T - Entire directory structure including Hidden one
$ 2T - Only Sub Dirs inside including Hidden one
$ *2T - Only Sub Dirs inside without Hidden one
$ ~2T - All Present users on system from "/etc/passwd"
$ $2T - All Sys variables
$ @2T - Entries from "/etc/hosts"
$ =2T - Output like ls or dir

FreeBSD & Linux Commands at your finger tips

2009-03-24T12:14:00.001+05:30

Would you like to have all the important Linux and FreeBSD commands with suitable examples fit in a couple of pages ? If you do, then you have got your wish.

Colin Barschel has put together what he calls the Unix Toolbox. This is a fabulous piece of compilation which contain all the frequently useful commands in Linux and their equivalents in FreeBSD. This document covers a wide range of topics divided into 22 sections such as system, processes, file systems, network related, VPN, cryptography, installing and managing software and so on.

What I really like about Unix toolbox is that it is well structured, each section has a Linux subsection immediately followed by a FreeBSD subsection which explains equivalent commands in FreeBSD. Secondly, the document is made available in multiple formats namely PDF, HTML page, booklet version fit to be printed and made into a small booklet and so on.

A very good resource for any Linux/FreeBSD enthusiast. There is also an additional bonus. Visit the homepage of this site and you get a FreeBSD console right within your web browser. As of now there are 30 commands which can be used. Colin has used the termlib library to create the virtual terminal.

Guide to Bash Shell Scripting

2009-03-24T11:20:00.003+05:30

First let me clarify that this is not going to be a detailed study of shell scripting, but as the name of the post indicates, it will be a quick reference to the syntax used in scripting for the bash shell. So if you are expecting the former, then you should buy yourself a good book on shell scripting . ;-) So let's move on to the guide. Start your stop watch now.

-- Start of The 10 secs Guide to Bash Scripting --

Common environment variables

PATH - Sets the search path for any executable command. Similar to the PATH variable in MSDOS.
HOME - Home directory of the user.
MAIL - Contains the path to the location where mail addressed to the user is stored.
IFS - Contains a string of characters which are used as word seperators in the command line. The string normally consists of the space, tab and the newline characters. To see them you will have to do an octal dump as follows:

$ echo $IFS | od -bc

PS1 and PS2 - Primary and secondary prompts in bash. PS1 is set to $ by default and PS2 is set to '>' . To see the secondary prompt, just run the command :

$ ls |

... and press enter.

USER - User login name.
TERM - indicates the terminal type being used. This should be set correctly for editors like vi to work correctly.
SHELL - Determines the type of shell that the user sees on logging in.

Note: To see what are the values held by the above environment variables, just do an echo of the name of the variable preceeded with a $. For example, if I do the following:

$ echo $USER
raja

... I get the value stored in the environment variable USER.

Some bash shell scripting rules

1) The first line in your script must be

#!/bin/bash

... that is a # (Hash) followed by a ! (ban) followed by the path of the shell. This line lets the environment know the file is a shell script and the location of the shell.

2) Before executing your script, you should make the script executable. You do it by using the following command:

$ chmod ugo+x your_shell_script.sh

3) The name of your shell script must end with a .sh . This lets the user know that the file is a shell script. This is not compulsary but is the norm.

Conditional statements

The 'if' Statement - evaluates a condition which accompanies its command line. Those words marked in blue are compulsory. But those marked in red are optional.

syntax:

if condition_is_true
then
execute commands
else
execute commands
fi

if condition also permits multiway branching. That is you can evaluate more conditions if the previous condition fails.

if condition_is_true
then
execute commands
elif another_condition_is_true
then
execute commands
else
execute commands
fi

Example :

if grep "linuxhelp" thisfile.html
then
echo "Found the word in the file"
else
echo "Sorry no luck!"
fi

if's companion - test
test is an internal feature of the shell. test evaluates the condition placed on its right, and returns either a true or false exit status. For this purpose, test uses certain operators to evaluate the condition. They are as follows:

Relational operators

-eq Equal to
-lt Less than
-gt Greater than
-ge Greater than or equal to
-lt Less than
-le Less than or equal to

File related tests

-f file True if file exists and is a regular file
-r file True if file exists and is readable
-w file True if file exists and is writable
-x file True if file exists and is executable
-d file True if file exists and is a directory
-s file True if file exists and has a size greater
than zero.

String tests

-n str True if string str is not a null string
-z str True if string str is a null string
str1 == str2 True if both strings are equal
str1 != str2 True if both strings are unequal
str True if string str is assigned a value
and is not null.

Test also permits the checking of more than one expression in the same line.

-a Performs the AND function
-o Performs the OR function

Example:

test $d -eq 25 ; echo $d

... which means, if the value in the variable d is equal to 25, print the value.

test $s -lt 50; do_something

if [ $d -eq 25 ]
then
echo $d
fi

In the above example, I have used square brackets instead of the keyword

test - which is another way of doing the same thing.

if [ $str1 == $str2 ]
then
do something
fi
if [ -n "$str1" -a -n "$str2" ]
then
echo 'Both $str1 and $str2 are not null'
fi

... above, I have checked if both strings are not null then execute the echo command.

Things to remember while using test

If you are using square brackets [] instead of test, then care should be taken to insert a space after the [ and before the ].

Note: test is confined to integer values only. Decimal values are simply truncated.

Do not use wildcards for testing string equality - they are expanded by the shell to match the files in your directory rather than the string.

Case statement

Case statement is the second conditional offered by the shell.

Syntax:

case expression in
pattern1) execute commands ;;
pattern2) execute commands ;;
...
esac

The keywords here are in, case and esac. The ';;' is used as option terminators. The construct also uses ')' to delimit the pattern from the action.

Example:

...
echo "Enter your option : "
read i;
case $i in
1) ls -l ;;
2) ps -aux ;;
3) date ;;
4) who ;;
5) exit
esac

Note: The last case option need not have ;; but you can provide them if you want.

Here is another example:

case `date |cut -d" " -f1` in
Mon) commands ;;
Tue) commands ;;
Wed) commands ;;
...
esac

Case can also match more than one pattern with each option.You can also use shell wild-cards for matching patterns.

...
echo "Do you wish to continue? (y/n)"
read ans
case $ans in
Y|y) ;;
[Yy][Ee][Ss]) ;;
N|n) exit ;;
[Nn][Oo]) exit ;;
*) echo "Invalid command"
esac

In the above case, if you enter YeS, YES,yEs and any of its combinations, it will be matched.

This brings us to the end of conditional statements.

Looping Statements

while loop

Syntax :

while condition_is_true
do
execute commands
done

Example:

while [ $num -gt 100 ]
do
sleep 5
done
while :
do
execute some commands
done

The above code implements a infinite loop. You could also write 'while true' instead of 'while :' .
Here I would like to introduce two keywords with respect to looping conditionals. They are break and continue.
break - This keyword causes control to break out of the loop.

continue - This keyword will suspend the execution of all statements following it and switches control to the top of the loop for the next iteration.

until loop

Until complements while construct in the sense that the loop body here is executed repeatedly as long as the condition remains false.

Syntax:

until false
do
execute commands
done

Example:

...
until [ -r myfile ]
do
sleep 5
done

The above code is executed repeatedly until the file myfile can be read.

for loop

Syntax :

for variable in list
do
execute commands
done

Example:

...
for x in 1 2 3 4 5
do
echo "The value of x is $x";
done

Here the list contains 5 numbers 1 to 5. Here is another example:

for var in $PATH $MAIL $HOME
do
echo $var
done

Suppose you have a directory full of java files and you want to compile those. You can write a script like this:

...
for file in *.java
do
javac $file
done

Note: You can use wildcard expressions in your scripts.

A few special symbols and their meanings w.r.t shell scripts

$* - This denotes all the parameters passed to the script
at the time of its execution. Which includes $1, $2
and so on.
$0 - Name of the shell script being executed.
$# - Number of arguments specified in the command line.
$? - Exit status of the last command.

The above symbols are known as positional parameters. Let me explain the positional parameters with the aid of an example. Suppose I have a shell script called my_script.sh . Now I execute this script in the command line as follows :

$ ./my_script.sh linux is a robust OS

... as you can see above, I have passed 5 parameters to the script. In this scenario, the values of the positional parameters are as follows:

$* - will contain the values 'linux','is','a','robust','OS'.
$0 - will contain the value my_script.sh - the name of the script being
executed.
$# - contains the value 5 - the total number of parameters.
$$ - contains the process ID of the current shell. You can use this parameter while giving unique names to any temporary files that you create at the time of execution of the shell.

$1 - contains the value 'linux'
$2 - contains the value 'is'
... and so on.

The set and shift statements

set - Lets you associate values with these positional parameters .

For example, try this:

$ set `date`
$ echo $1
$ echo $*
$ echo $#
$ echo $2

shift - transfers the contents of a positional parameter to its immediate lower numbered one. This goes on as many times it is called.

Example :

$ set `date`
$ echo $1 $2 $3
$ shift
$ echo $1 $2 $3
$ shift
$ echo $1 $2 $3

To see the process Id of the current shell, try this:

$ echo $$
2667

Validate that it is the same value by executing the following command:

$ ps -f |grep bash

read statement

Make your shell script interactive. read will let the user enter values while the script is being executed. When a program encounters the read statement, the program pauses at that point. Input entered through the keyboard id read into the variables following read, and the program execution continues.

Eg:

#!/bin/sh
echo "Enter your name : "
read name
echo "Hello $name , Have a nice day."

Exit status of the last command

Every command returns a value after execution. This value is called the exit status or return value of the command. A command is said to be true if it executes successfully, and false if it fails. This can be checked in the script using the $? positional parameter.

Here I have given a concise introduction to the art of bash shell scripting in Linux. But there is more to shell scripting than what I have covered. For one, there are different kinds of shells, bash shell being only one of them. And each shell has a small variation in its syntax. Like the C shell for example, which uses a syntax close to the C language for scripting. But what I have covered above applys to all the shells.

5 Easy Ways to Download YouTube Videos To Your Computer

2009-03-23T20:36:00.002+05:30

Online video streaming has been the rage for some time now – and we can view countless videos through sites like YouTube and Metacafe - but what happens if you find a video you really like and would like to store it for offline viewing or to watch it on a mobile device? Unfortunately, we are limited only to streaming as there is no option to download the videos on YouTube. Well, fret not as we have at our disposal easy-to-use tools that make downloading such videos possible.

1. How to Download Videos with One Click

KeepVid is a web-based video downloader. Perfect for those who are on the go or do not wish to install additional applications on their computer, KeepVid oozes simplicity and idiot-proof video downloading. To download YouTube videos, simply copy the URL of the YouTube video page you wish to download, and paste it in the Keepvid Textbox. A link will then appear which allows you to save the .flv video file to your computer! As an added bonus, KeepVid can also download videos from several other video streaming services such as Metacafe. It also comes with a bookmarklet so you can download any video you’re watching with one click.

2. How to Download Videos Directly from the URL Box

Another funky and ingenious method to download videos from YouTube is to add a kiss to the video you wish to download, literally! How would you do that? Simple, just add the word ‘kiss’ in front of the ‘youtube’ word in the URL and press enter. You will then be brought to the download page with a link to the .flv video. For example, say we want to download this Super Bowl video. The original URL would be “http://www.youtube.com/watch?v=9jxyYwrKIKQ”. Now just add a kiss, and make it “http://www.kissyoutube.com/watch?v=9jxyYwrKIKQ” for the download. Simple as that! Java is required for this website to work, though.

3. How to Convert .flv Videos On The Fly

Now this is a tool you won’t want to miss! Vixy.net is both a web-based YouTube video downloader and converter! While many popular media players such as Windows Media Player and Quicktime aren’t capable of playing back .flv extensions (which YouTube videos are streamed in), Vixy.net solves those problems by offering a free conversion service along with any download. After entering the URL of the desired video, just choose the file type you wish to convert into (there is AVI, 3GP, and MOV, among others). This is a truly convenient way of making YouTube videos more accessible to other media players.

4. Where to Find YouTube Download Software

For those who fancy having gadgets and utilities lying around their computer desktops, YouTube Downloader is the perfect tool! As a free download from Download.com, this nifty little program can easily download YouTube videos – just copy and paste the video URL and press the button! Its additional feature includes a built-in video converter to convert downloaded .flv files into other more convenient formats.

5. Where to Find an Awesome Firefox Plugin to Download Videos

Firefox fans rejoice! Now there is a quick and convenient way to extract your favorite YouTube videos using this add-on. Besides YouTube, this plug-in supports other video streaming sites including Metacafe, Google Videos and Dailymotion, among others. Just surf like normal and when DownloadHelper detects a downloadable object, its icon will animate, allowing you to download the streaming video.

Would you download a youtube video? Tell me in the comments!

Linux file system hierarchy

2009-03-23T16:10:00.002+05:30

I have been asked by many people to explain the file system hierarchy in Linux because they find the file system in Linux quite different from what they are used to in Windows. To put it simply, it can be visualized as a tree with its roots and all. At the top of the hierarchy is invariably the root path which is represented by '/'. All other directories are created beneath this root path. And each of the sub directories have a specific purpose. For example, '/etc' contain the configuration files, the '/opt' directory is used to install third party software, '/boot' contain the grub files and the Linux kernel and so on.

source: Linuxconfig

Fig: Linux file system hierarchy

How To Get Hardware Information On Linux Using dmidecode Command

2009-03-23T15:53:00.002+05:30

dmidecode command reads the system DMI table to display hardware and BIOS information of the server. Apart from getting current configuration of the system, you can also get information about maximum supported configuration of the system using dmidecode. For example, dmidecode gives both the current RAM on the system and the maximum RAM supported by the system.

This article provides an overview of the dmidecode and few practical examples on how to use dmidecode command.

1. Overview of dmidecode

Distributed Management Task Force maintains the DMI specification and SMBIOS specification. The output of the dmidecode contains several records from the DMI (Desktop Management interface) table.

Following is the record format of the dmidecode output of the DMI table.

Record Header: Handle {record id}, DMI type {dmi type id}, {record size} bytes
Record Value: {multi line record value}

record id: Unique identifier for every record in the DMI table.
dmi type id: Type of the record. i.e BIOS, Memory etc.,
record size: Size of the record in the DMI table.
multi line record values: Multi line record value for that specific DMI type.

Sample output of dmidecode command:

# dmidecode | head -15

# dmidecode 2.9
SMBIOS 2.3 present.
56 structures occupying 1977 bytes.
Table at 0×000FB320.

Handle 0xDA00, DMI type 218, 11 bytes
OEM-specific Type
       Header and Data:
               DA 0B 00 DA B0 00 17 03 08 28 00

Handle 0×0000, DMI type 0, 20 bytes
BIOS Information
       Vendor: Dell Computer Corporation
       Version: A07
       Release Date: 01/13/2004

Get the total number of records in the DMI table as shown below:

# dmidecode | grep ^Handle | wc -l
56

(or)

# dmidecode | grep structures
56 structures occupying 1977 bytes.

2. DMI Types

DMI Type id will give information about a particular hardware component of your system. Following command with type id 4 will get the information about CPU of the system.

# dmidecode -t 4
# dmidecode 2.9
SMBIOS 2.3 present.

Handle 0×0400, DMI type 4, 35 bytes
Processor Information
       Socket Designation: Processor 1
       Type: Central Processor
       Family: Xeon
       Manufacturer: Intel
       ID: 29 0F 00 00 FF FB EB BF
       Signature: Type 0, Family 15, Model 2, Stepping 9
       Flags:
               FPU (Floating-point unit on-chip)
               VME (Virtual mode extension)
               DE (Debugging extension)
               PSE (Page size extension)
               TSC (Time stamp counter)
               MSR (Model specific registers)

Following are the different DMI types available.

       Type   Information
      ----------------------------------------
         0   BIOS
         1   System
         2   Base Board
         3   Chassis
         4   Processor
         5   Memory Controller
         6   Memory Module
         7   Cache
         8   Port Connector
         9   System Slots
        10   On Board Devices
        11   OEM Strings
        12   System Configuration Options
        13   BIOS Language
        14   Group Associations
        15   System Event Log
        16   Physical Memory Array
        17   Memory Device
        18   32-bit Memory Error
        19   Memory Array Mapped Address
        20   Memory Device Mapped Address
        21   Built-in Pointing Device
        22   Portable Battery
        23   System Reset
        24   Hardware Security
        25   System Power Controls
        26   Voltage Probe
        27   Cooling Device
        28   Temperature Probe
        29   Electrical Current Probe
        30   Out-of-band Remote Access
        31   Boot Integrity Services
        32   System Boot
        33   64-bit Memory Error
        34   Management Device
        35   Management Device Component
        36   Management Device Threshold Data
        37   Memory Channel
        38   IPMI Device
        39   Power Supply

Instead of type_id, you can also pass the keyword to the -t option of the dmidecode command. Following are the available keywords.

       Keyword     Types
      ------------------------------
      bios        0, 13
      system      1, 12, 15, 23, 32
      baseboard   2, 10
      chassis     3
      processor   4
      memory      5, 6, 16, 17
      cache       7
      connector   8
      slot        9

For example, to get all the system baseboard related information execute the following command, which will display the type_id 2 and 10

# dmidecode -t baseboard
# dmidecode 2.9
SMBIOS 2.3 present.

Handle 0×0200, DMI type 2, 9 bytes
Base Board Information
       Manufacturer: Dell Computer Corporation
       Product Name: 123456
       Version: A05
       Serial Number: ..CN123456789098.

Handle 0×0A00, DMI type 10, 14 bytes
On Board Device 1 Information
       Type: SCSI Controller
       Status: Enabled
       Description: LSI Logic 53C1030 Ultra 320 SCSI
On Board Device 2 Information
       Type: SCSI Controller
       Status: Enabled
       Description: LSI Logic 53C1030 Ultra 320 SCSI
On Board Device 3 Information
       Type: Video
       Status: Enabled
       Description: ATI Rage XL PCI Video
On Board Device 4 Information
       Type: Ethernet
       Status: Enabled
       Description: Broadcom Gigabit Ethernet 1
On Board Device 5 Information
       Type: Ethernet
       Status: Enabled
       Description: Broadcom Gigabit Ethernet 2

3. Get Physical Memory (RAM) information using dmidecode

What is the maximum RAM supported by the system? In this example, this system can support maximum 8GB of RAM.

# dmidecode -t 16
# dmidecode 2.9
SMBIOS 2.3 present.

Handle 0×1000, DMI type 16, 15 bytes
Physical Memory Array
       Location: System Board Or Motherboard
       Use: System Memory
       Error Correction Type: Multi-bit ECC
        Maximum Capacity: 8 GB
        Error Information Handle: Not Provided
       Number Of Devices: 4

How much memory can I expand to? From /proc/meminfo you can find out the total current memory of your system as shown below.

# grep MemTotal /proc/meminfo
MemTotal:      1034644 kB

In this example, the system has 1GB of RAM. Is this 1 x 1GB (or) 2 x 512MB (or) 4 x 256MB? This can be figured out by passing the type id 17 to the dmidecode command as shown below. Please note in the example below, if you have to expand upto 8GB of maximum RAM, you need to remove the existing 512MB from slot 1 and 2, and use 2GB RAM on all the 4 memory slots.

# dmidecode -t 17
# dmidecode 2.9
SMBIOS 2.3 present.

Handle 0×1100, DMI type 17, 23 bytes
Memory Device
       Array Handle: 0×1000
       Error Information Handle: Not Provided
       Total Width: 72 bits
       Data Width: 64 bits
        Size: 512 MB  [Note: Slot1 has 512 MB RAM]
       Form Factor: DIMM
       Set: 1
       Locator: DIMM_1A
       Bank Locator: Not Specified
       Type: DDR
       Type Detail: Synchronous
       Speed: 266 MHz (3.8 ns)

Handle 0×1101, DMI type 17, 23 bytes
Memory Device
       Array Handle: 0×1000
       Error Information Handle: Not Provided
       Total Width: 72 bits
       Data Width: 64 bits
        Size: 512 MB [Note: Slot2 has 512 MB RAM]
       Form Factor: DIMM
       Set: 1
       Locator: DIMM_1B
       Bank Locator: Not Specified
       Type: DDR
       Type Detail: Synchronous
       Speed: 266 MHz (3.8 ns)

Handle 0×1102, DMI type 17, 23 bytes
Memory Device
       Array Handle: 0×1000
       Error Information Handle: Not Provided
       Total Width: 72 bits
       Data Width: 64 bits
        Size: No Module Installed [Note: Slot3 is empty]
       Form Factor: DIMM
       Set: 2
       Locator: DIMM_2A
       Bank Locator: Not Specified
       Type: DDR
       Type Detail: Synchronous
       Speed: 266 MHz (3.8 ns)

Handle 0×1103, DMI type 17, 23 bytes
Memory Device
       Array Handle: 0×1000

       Error Information Handle: Not Provided
       Total Width: 72 bits
       Data Width: 64 bits
        Size: No Module Installed [Note: Slot4 is empty]
       Form Factor: DIMM
       Set: 2
       Locator: DIMM_2B
       Bank Locator: Not Specified
       Type: DDR
       Type Detail: Synchronous
       Speed: 266 MHz (3.8 ns)

4. Get BIOS information using dmidecode

# dmidecode -t bios
# dmidecode 2.9
SMBIOS 2.3 present.

Handle 0×0000, DMI type 0, 20 bytes
BIOS Information
       Vendor: Dell Computer Corporation
       Version: A07
       Release Date: 01/13/2004
       Address: 0xF0000
       Runtime Size: 64 kB
       ROM Size: 4096 kB
       Characteristics:
               ISA is supported
               PCI is supported
               PNP is supported
               BIOS is upgradeable
               BIOS shadowing is allowed
               ESCD support is available
               Boot from CD is supported
               Selectable boot is supported
               EDD is supported
               Japanese floppy for Toshiba 1.2 MB is supported (int 13h)
               5.25″/360 KB floppy services are supported (int 13h)
               5.25″/1.2 MB floppy services are supported (int 13h)
               3.5″/720 KB floppy services are supported (int 13h)
               8042 keyboard services are supported (int 9h)
               Serial services are supported (int 14h)
               CGA/mono video services are supported (int 10h)
               ACPI is supported
               USB legacy is supported
               LS-120 boot is supported
               BIOS boot specification is supported
               Function key-initiated network boot is supported

Handle 0×0D00, DMI type 13, 22 bytes
BIOS Language Information
       Installable Languages: 1
               en|US|iso8859-1
       Currently Installed Language: en|US|iso8859-1

5. View Manufacturer, Model and Serial number of the equipment using dmidecode

You can get information about the make, model and serial number of the equipment as shown below:

# dmidecode -t system
# dmidecode 2.9
SMBIOS 2.3 present.

Handle 0×0100, DMI type 1, 25 bytes
System Information
       Manufacturer: Dell Computer Corporation
       Product Name: PowerEdge 1750
       Version: Not Specified
       Serial Number: 1234567
       UUID: 4123454C-4123-1123-8123-12345603431
       Wake-up Type: Power Switch

Handle 0×0C00, DMI type 12, 5 bytes
System Configuration Options
       Option 1: NVRAM_CLR:  Clear user settable NVRAM areas and set defaults
       Option 2: PASSWD:  Close to enable password

Handle 0×2000, DMI type 32, 11 bytes
System Boot Information
       Status: No errors detected

WOL Wakeonlan Guide: Turn On Servers Remotely Without Physical Access

2009-03-23T15:46:00.001+05:30

Wakeonlan (wol) enables you to switch ON remote servers without physically accessing it. Wakeonlan sends magic packets to wake-on-LAN enabled ethernet adapters and motherboards to switch on remote computers.

By mistake, when you shutdown a system instead of rebooting, you can use Wakeonlan to power on the server remotely. Also, If you have a server that don’t need to be up and running 24×7, you can turn off and turn on the server remotely anytime you want.

This article gives a brief overview of Wake-On-LAN and instructions to set up Wakeonlan feature.

Overview of Wake-On-LAN

You can use Wakeonlan when a machine is connected to LAN, and you know the MAC address of that machine.
Your NIC should support wakeonlan feature, and it should be enabled before the
shut down. In most cases, by default wakeonlan is enabled on the NIC.
You need to send the magic packet from another machine which is connected to the same network ( LAN ). You need root access to send magic packet. wakeonlan package should be installed on the machine.
When the system crashes because of power failure, for the first time you cannot switch on your machine using this facility. But after the first first boot you can use wakeonlan to turn it on, if the server gets shutdown for some reason.
WakeonLan is also referred as wol.

Check whether wol is supported on the NIC

Execute the following ethtool command in the server which you want to switch ON from a remote place.

# ethtool eth0
Settings for eth0:
      Supported ports: [ TP MII ]
      Supported link modes:   10baseT/Half 10baseT/Full
                              100baseT/Half 100baseT/Full
      Supports auto-negotiation: Yes
      Advertised link modes:  10baseT/Half 10baseT/Full
                              100baseT/Half 100baseT/Full
      Advertised auto-negotiation: Yes
      Speed: 100Mb/s
      Duplex: Full
      Port: MII
      PHYAD: 1
      Transceiver: internal
      Auto-negotiation: on
      Supports Wake-on: pumbg  [ Note: check whether flag g is present ]
      Wake-on: g [ Note: g mean enabled. d means disabled ]
      Current message level: 0×00000001 (1)
      Link detected: yes

If Supports Wake-on is g, then the support for wol feature is enabled on the NIC card.

Enabling wol option on the Ethernet Card

By default the Wake-on will be set to g in most of the machines. If not, use ethtool to set the g flag to the wol option of the NIC card as shown below.

# ethtool -s eth0 wol g

Note: You should execute ethtool as root, else you may get following error message

$ /sbin/ethtool eth0
Settings for eth0:
Cannot get device settings: Operation not permitted
Cannot get wake-on-lan settings: Operation not permitted
      Current message level: 0×000000ff (255)
Cannot get link status: Operation not permitted

Install wakeonlan package on a different machine

Install the wakeonlan package in the machine from where you need to send the magic packet to switch on your server.

# apt-get install wakeonlan

Note down the MAC address of the remote server

Note down the MAC address of the server that you wish to switch on remotely.

# ifconfig
eth0     Link encap:Ethernet  HWaddr 00:16:k5:64:A9:68  [ Mac address ]
        inet addr:192.168.6.56  Bcast:192.168.6.255  Mask:255.255.255.0
        inet6 addr: fe80::216:17ff:fe6b:289/64 Scope:Link
        UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
        RX packets:3179855 errors:0 dropped:0 overruns:0 frame:0
        TX packets:2170162 errors:0 dropped:0 overruns:0 carrier:0
        collisions:0 txqueuelen:1000
        RX bytes:3832534893 (3.5 GB)  TX bytes:390304845 (372.2 MB)
        Interrupt:17

Finally, Switch ON the machine remotely without physical access

When the server is not up, execute the following command from another machine which is connected to the same LAN. Once the magic packet is sent, the remote system will start to boot.

# wakeonlan 00:16:k5:64:A9:68