Saturday, September 26, 2009

List All Users in Linux

To list all the users who can access a Linux machine we have to access the /etc/passwd file, which stores information about all registered users of that machine. But it is not really so easy as told above since the file contains many other fields & machine trust accounts & inbuilt accounts.

We'll start by
cat /etc/passwd

As we all know that by default all the users created will have their home directories in /home share so we'll modify our command a bit by using grep. Now it'll be
cat /etc/passwd | grep "/home"

Now we'll get all the user accounts which have their home share in /home.But the only output we need is the list of users & nothing else. So we'll modify our command again
cat /etc/passwd | grep "/home" |cut -d: -f1

Now what we have done is that we have piped the output of previous command to another variable "cut"

What we have done here is we have added cut -d: -f1
-d: means delimiter :
-f1 means display first field of line i.e. username.

So final command is
cat /etc/passwd | grep "/home" |cut -d: -f1
This works until all your users have their home share in /home. If you have defined their home share to some other destination. Modify the above command accordingly.

Wine 1.1.30 Released

The Wine development release 1.1.30 is now available.

What's new in this release:

* Support for OpenAL.
* Many improvements in HTML and JavaScript support.
* Many common controls fixes and improvements.
* More Direct3D 10 work.
* Better MAPI support.
* Various bug fixes.

The source is available now. Binary packages are in the process of being built, and will appear soon at their respective download locations.

Sunday, September 20, 2009

Use the Terminal to Display a Calendar in Ubuntu

Using Ubuntu’s Terminal, you can quickly pull up a calendar of any month or year

1. Open a Terminal window.
2. To view a single month, execute the following Terminal command (make sure to input both the desired month and year):

cal december 2008

To view an entire year, execute the following Terminal command (make sure to input the desired year):

cal 2009

To view last month, this month and next month, execute the following Terminal command:

cal -3

Display calendar in alternative layout for calendar

The alternative layout of the calendar can be displayed using ncal command.


ncal june 2009

Welcome Ubuntu 10.04 “Lucid Lynx”!

Mark Shuttleworth has announced the new version to UbuCon at the Atlanta Linux Fest. Here is the Youtube video:

In the video the code name for Ubuntu 10.04 is revealed: “Lucid Lynx”. This will be a LTS release.The main points to consider are, “Lucid Lynx” will focus on GNOME 2 rather than GNOME 3, which will be adopted in subsequent releases. The server edition will focus on cloud computing and support for large scale web infrastructure.

Ubuntu 10.04 will be released in April 2010.

Here is the Wikepedia article for Lynx.
This is how a Lynx looks:

Sunday, September 13, 2009

3 Tools For Chemistry Students Using Ubuntu

BKChem is a chemical drawing Ubuntu chemistry software that’s packed with features.
bond-by-bond drawing
bond lenght and angle restrictions to assist with the drawing
ready to use templates of common rings
ability to expand common groups from abbreviated to structural form
Support for linear formulas (such as -CH2CH(COOCH3)2)
radicals, charges...
arrows (several types - normal, retro, equilibrium, etc.)
rich text
color support
simple vector graphics (rectangles, circles, polygons etc.)
unlimited undo and redo capabilities
rotation (2D, 3D)
aligning of molecules so that particular bond is horizontal/vertical
rotation of molecular fragments around bonds (conformation changes)
definition of personal preferred drawing style (bond lenghts, widths, colors...)
full export to SVG (native data are transparently embedded into SVG file)
full export to OpenOffice Draw format
full export to ODF (OpenOffice 2.0) format
full export to Encapsulated PostScript
full export to PDF
full export to PNG (if pycairo is installed, available in Windows binary build)
basic support for both CML1 and CML2
generation of SMILES
basic support for both CML1 and CML2
SMILES (subset)
INChI (subset)
Other features
localization support (currently English, French, Czech, Polish, German and Traditional Chinese translations are available)
native format is XML based
validity checking of drawn structures
support for user written plugins
support for user written batch scripts
searching for BKChem files containing specified molecules or molecule fragment

Chemical Calculator or GChemCalc is another Ubuntu chemistry software app that’s a simple chemical calculator for determining molecular weights of a formula and their respective percentages, all really fast and easy. There’s not much to be said about it, except I use it all the time – simple is almost always better.

Kalzium provides you with all kinds of information about elements in the Periodic Table of the Elements. You can lookup information about the elements and also use visualizations to show them. It is free and licensed under the GNU Public License.
You can visualize the Periodic Table of the Elements by groups, blocks, and families. You can plot data for a range of elements for properties like the boiling point or the atomic mass and can go back in time and see what elements were known at a given data.
Kalzium is divided in a navigation panel on the left and the table view which shows the elements of the periodic table. The standard menu bar allows you to choose what you want to display and the status bar reports facts. You can hide the navigation panel by using the View->Show Sidebar menu.
When you move the mouse cursor on an element of the table, an overview of the current element in the Overview tab of the navigation panel will be displayed. You can choose  several views for the table: display the elements per families, per groups, per crystal structure, depending on their acidic behavior, etc. You can change all that in the menu bar in the View->Scheme menu. If you want to know facts about a precise element, click on it in the table and the information dialog will be displayed.You can also calculate the molecular mass of molecules with the tool in its sidebar. You can enter linear formulas to calculate their weight.

You can install any of the Ubuntu chemistry software applications discussed in this article by searching for their name in the Synaptic Package Manager, checking the box on the left of its name and clicking ”Apply Changes”. To launch Synaptic, choose System > Administration > Synaptic Package Manager.

Saturday, September 5, 2009

Install 3.1.1 in Ubuntu

To install the latest release using command-line, just use the instructions below:

First, edit the /etc/apt/sources.list file and enter your user password:

sudo nano /etc/apt/sources.list

Add the following two lines (the second one is not necessary, unless you want the sources to be available too):

deb jaunty main
deb-src jaunty main

Add the trusted key for these repositories:

sudo apt-key adv --keyserver --recv-keys 247D1CFF

Update the packages lists:

sudo apt-get update

You can eventually remove your existing OpenOffice installation by using the following two commands:

sudo apt-get remove --purge

sudo apt-get autoremove --purge

This will also remove system-wide configuration files.

Now, install 3.1.1:

sudo apt-get install

This should be all. You can run it by pressing Alt+F2 and typing openoffice in the run box.

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