Category Archives: Technology

Create ‘alias’ (shortcuts to commands) using Linux Sophisticated Commands

Long sophisticated instructions are usually not solely tough to recollect but in addition  take a lot of time to be typed. When it’s a must to use them on day by day foundation, you turn into annoyed when typing them repeatedly and again… So, ‘alias’ are extra appropriate for lengthy and complex commands.

Let’s think about an example.

To find the top 10 largest files in your system, you can set the next ‘alias’:

alias top10files=”find . -type f -exec ls -sh {} \; | sort -n -r | head -10”

You can even combine different instructions with ‘alias’.  As an illustration, if you happen to often use ‘tail’ and direct its output to file to later view that file, you may set a very simple ‘alias’ to do this cumbersome operation in 1 word:

alias Tail=”tail /var/log/messages > hello.txt;cat hello.txt”

Now just enter ‘Tail’ and voila! All is done at once.

You need to use any file with tail and direct its output and you’ll even use ‘nano’ or ‘vi’ to view/edit its output.

Here’s one other example… ‘alias’ to connect to a remote server:

alias any_name=”ssh -l -p ”

You possibly can even create ‘alias’ on your bash scripts, like:

alias clc=”sh /home/user/myscripts/calc.sh”

Now that you have set a number of totally different ‘alias’  you may want to test that which ‘alias’ are set in your system.  To do that, simply difficulty the next command:

alias

and it will list all the set ‘alias’ you have.

To remove an ‘alias’, just issue the ‘unalias’ command, like:

unalias Google

and now typing Google in Terminal will do nothing (as it was set with lynx).

To remove all the ‘alias’, issue the following command and all the ‘alias’ are gone:

unalias -a

We have mentioned the way in which of setting the ‘alias’ for different sorts of commands.  However setting ‘alias’ in this approach be temporary.  While you reboot you PC, all the ‘alias’ which you will have set will probably be gone.  This does not mean that it’s a must to set all of the ‘alias’ each time you boot your PC.  You probably have set an ‘alias’ and you favored it a lot that you really want it to completely reside in you PC, simply add this alias in ‘.bashrc’ file in you dwelling directory. For example, if you would like ‘alias’:

Set up <software_name>

to permanently reside in your PC then user your favorite text editor and add the following line in your ‘~/.bashrc’ file:

alias Install=”sudo apt-get install”

Now this ‘alias’ will not vanish into thin air when you reboot your PC. Only those ‘alias’  which are listed in ‘~/.bashrc’ file will be permanent.

This information is just a preview about ‘alias’.  It’s just about primary ways of using ‘alias’ to make your life simpler.  ‘GNU alias’ is a instrument which can simplify your life immensely.  But sadly this device isn’t given the attention it deserves.  Briefly, it is such a strong tool that when you give it proper time, it could possibly make you overlook typing. AddThis mp3 link

Ubuntu to Windows XP folder sharing

Computer networks are sometimes comprised of various OS and while operating a network made up fully of Ubuntu desktop and server computer systems would definitely be enjoyable, some community environments can consist of both Ubuntu and Microsoft Windows systems working together.
If you want to make an Ubuntu shared folder be accessible to Windows XP,  run the NTFS configuration tool on the drive.
Don’t forget that it is advisable to have admin rights to do that modification.
Select application->Accessories->Terminal
then type the following:

sudo gedit /etc/samba/smb.conf

and in the [global] section add the following line:

usershare proprietor only = false

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Enabling remote desktop on a VirtualBox Machine

To enable remote desktop on a VirtualBox machine, you have to follow these steps:
VBoxManage modifyvm MachineName -vrdp
This command enables rdp on the virtual machine
VBoxManage startvm MachineName -type vrdp

It starts virtual machine, listening for rdp request on port 3389 (default port)
rdesktop-vrdp localhost

Connects virtual machine with rdp (You can use rdesktop too).
If you want to change rdp port, use this command:
VBoxManage modifyvm MachineName -vrdpport

Also, enabling authentication for rdp is possible:
VBoxManage modifyvm MachineName -vrdpauthtype null | external | guest

VBoxManage is the command line interface of the VirtualBox.
You can make these settings with GUI: Settings -> Remote Display -> Enable VRDP Server
If you want to use your virtual machine with vrdp only, you can use this command simply:
VBoxHeadless -startvm MachineName

Note: RDP server is not included in Open Source Edition of the VirtualBox. If you want to use this feature, you have to use closed-source edition. AddThis mp3 link

Using iPhone internet sharing over bluetooth under Linux

To use your iPhone’s internet connection through a Linux notebook over bluetooth, you have to open Tethering option on your iPhone device, under the Settings->General->Network section.

After that you can install Blueman (a simple and intuitive bluetooth manager) for easily configuring bluetooth PAN network:

apt-get install blueman

Start blueman-manager and find your mobile device and connect to it. When connection completed successfully, select Device->Add->Network Access Point in blueman-manager.
And the last step, configure the network interface:

dhclient bnep

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Logwatch on Ubuntu Desktop/Server

Logwatch is an Ubuntu modular log analyzer that runs every night and mails you the results. It can also be run from command line. The output is by service and you can limit the output to one particular service. The subscripts which are responsible for the output, mostly convert the raw log lines in structured format.
Logwatch generally ignores the time component in the output, that means, you will know that the reported event was logged in the requested range of time, but you will have to go to the raw log files to get the exact details.
Install logwatch using the following command:

sudo apt-get install logwatch

This will install all the required packages

Configuring Logwatch:

first you need to make sure you server is able to send the mails outside you can do this using postfix with SMTP server configuration.

Now you need to edit logwatch.conf file:

sudo nano /usr/share/logwatch/default.conf/logwatch.conf

Change the following information:

Output = mail
Format = html
MailTo = test@gmail.com

Save and exit the file

If you want to know more available options check logcheck manpage using the following command from your terminal:

man logcheck

Now edit the 00logwatch file

sudo nano /etc/cron.daily/00logwatch

add the following line:

/usr/sbin/logwatch –mailto test@gmail.com

Save and exit the file

This tool is very useful, give it a try! AddThis mp3 link

Maximize internet speed connection in Ubuntu via sysctl

Do you want to maximize your bandwidth? Here are few important settings you should do to speed up your internet and it works in Ubuntu and all Linux operating system via sysctl.
First open a Terminal via Applications->Accessories->Terminal
Type:

sudo gedit /etc/sysctl.conf

Then Paste the Following at the end of the file:

# increase TCP max buffer size setable using setsockopt()
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
# increase Linux autotuning TCP buffer limits
# min, default, and max number of bytes to use
# set max to at least 4MB, or higher if you use very high BDP paths
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
# don’t cache ssthresh from previous connection
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_moderate_rcvbuf = 1
# recommended to increase this for 1000 BT or higher
net.core.netdev_max_backlog = 2500
# for 10 GigE, use this, uncomment below
# net.core.netdev_max_backlog = 30000
# Turn off timestamps if you’re on a gigabit or very busy network
# Having it off is one less thing the IP stack needs to work on
#net.ipv4.tcp_timestamps = 0
# disable tcp selective acknowledgements.
net.ipv4.tcp_sack = 0
#enable window scaling
net.ipv4.tcp_window_scaling = 1

Press Ctrl-S to save, then alt-F4 to exit and then type:

sudo sysctl -p

to apply the settings.

Now, check your speed using speed-test site or download files in the net.

You can disable all these settings by removing these lines you added via:

sudo gedit /etc/sysctl.conf

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Open Source tools and applications for web developers

Several open source tools have evolved in the past and have become popular with the developers too.  These tools have gained popularity not only because they come free but because of the ease to work with and the features.  First let us see some code editors:

Aptana:  It is a free, JavaScript focused development environment, cross-platform and open source for building Ajax applications.  It supports HTML, JavaScript, CSS languages, FTP/SFTP and has a powerful JavaScript debugger that can help in troubleshooting your code.

Eclipse :  It is an open source software framework written mainly in Java.  It is an integrated development environment consisting Java development toolkit (JDK) and compiler (ECJ) for developing applications in Java.  Developers can extend its capabilities by installing plug-ins such as development toolkits for other programming languages written specifically for eclipse software framework.  Language packs for over a dozen languages are available.

JEdit : It is a programmer’s text editor which has many hundreds of man-hours of development behind it. It is a java-based solution  and a cross-platform product  which can work on many operating systems like Windows, VMS, UNIX,  OX/2 and Mac OS X.

NVU : It is a web authoring system for Linux desktop users, Macintosh users as well as for Microsoft windows and  is a competitor for similar products like Dreamweaver and Frontpage.  Nvu actually means new view and makes managing a website very easy.  Now even people without knowledge of HTML or technical expertise can create web pages and manage a website.

Quanta Plus : It is a web development environment with a lot of features and is highly stable.   Quanta has a vision of achieving maximal user extensibility through the best architectural foundations, best, efficient design and natural use of code.

We shall see other tools in other posts. AddThis mp3 link

Ubuntu to Windows XP folder sharing

Computer networks are sometimes comprised of various methods, and while operating a network made up fully of  Ubuntu desktop and server computer systems would definitely be enjoyable, some community environments must consist of both Ubuntu and Microsoft Windows systems working collectively in harmony.
When making an Ubuntu shared folder that was created with NTFS be accessible to Windows XP steps. Run the NTFS configuration tool on the drive.
It is advisable have admin rights to do that modification.
Select: Application –> Accessories –>Terminal
then type the following:

sudo gedit /etc/samba/smb.conf

In the [global] section, add the following line:

usershare proprietor only = false

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Some Linux security tips for Rootkit Hunter

If you run Rootkit Hunter and you haven’t modified your stock Red Hat configuration of the SSH service (sshd), chances are it will find that you allow root logins. Rootkit Hunter considers these as possible security risks. However, to fix this, you can simply login as root, fire up a text editor, and edit the file

/etc/ssh/sshd_config

Make the following changes:
You’ll find a commented line like this:
#Protocol 2,1
Uncomment it and change it to:
Protocol 2
This will disallow logins using the older versions of the protocol

Look for the commented line
#PermitRootLogin yes
Uncomment the line and change it so it reads:
PermitRootLogin no
This will configure sshd NOT to allow root logins.

After this, be sure to restart sshd (assuming you run the service in the first place so:
Service sshd restart

By the way Rootkit scanner is scanning tool to ensure you for about 99.9% you’re clean of nasty tools. This tool scans for rootkits, backdoors and local exploits.

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Get Kindle for PC to Ubuntu (if you really don’t like Calibre)

Amazon’s Kindle a popular portable e-book reader device, lately made Kindle for PC application that allows you to download and have books on your computer rather than having a portable e-book reader device. There’s only Kindle Windows version but the nice thing is you can have this application in Linux.
This is tested in Ubuntu 9 running Gnome. You can use different version of Linux, but first you must have Wine HQ installed to you computer. Then download the EXE file of Kindle for PC application in Amazon.
Install this with Wine HQ software loader and proceed to the normal installation, the same thing that you do in Windows environment.
Note:

– At your first run you won’t see anything at all

– Configure Wine first and add Kindle for PC as an application and make it run in Windows 98 mode

– If it won’t work, change to other mode

– When it opens successfully you have to input you Amazon email add and password to register the software.

But, please, don’t forget that if you prefer open source software, you can directly use Calibre, a powerful free software we posted a while ago. AddThis