Ubuntu -- Analysis of the versions 8, 9 and 10

Ubuntu, a variant of Linux is continuously making its mark in the race among the operating systems as advancements are being made continuously with respect to many operating system aspects. I found huge advancements in regions such as GUI, CPU Utilisation, Networking, booting time etc. though some features were getting down. The Ubuntu Operating system versions will be released in the April and October months of every year with advancements made in some operating system aspects.

The versions and the code names of Ubuntu are given below:

8.04          HARDY HERON
8.10          INTREPID IBEX
9.04          JAUNTY JACKALOPE
9.10          KARMIC KOALA
10.04        LUCID LYNX
10.10        MAVERICK MEERKAT

The Ubuntu versions 8.04 and 8.10 had nothing to talk much about them. The software packages were not efficiently run besides the high CPU utilisation. The security settings were also not that strong. Networking was not good and connection to Internet through DSL was not present in Ubuntu 8.04. The look and feel was not appealing and the dependencies had to be looked after every now and then while installing the software packages. The Web Browser consumed much of the CPU resources when it was running, making it uncomfortable to use.

The Ubuntu versions 9.04 and 9.10 started using ext4 file system which made them to reduce the boot times three times than that of the 8.10 version. These versions boot in 25 seconds much better than the 65 seconds taken by the previous version (8.10). With the same, it managed to efficiently improve the system performance. These versions also made the look and feel better by introducing an absolute candy for notification purposes. The Empathy Instant messenger came into play with the version 9.10. The wireless network support was included in the 9.04 version. However, the network applet had some bugs, which made the connection to Internet (Wired using DSL) difficult. Besides all this, the Jaunty Jackalope newly had Tablet and Netbook support.

I should say that Ubuntu 10.04 and Ubuntu 10.10 are the best which we are having at present. These versions take only 10 seconds for the booting purpose, much better than the previous releases (25 seconds in the previous releases). In addition to the booting time, the software seemed to start quickly. The GUI has changed suddenly and the default theme settings are appealing to the eyes. The Internet got very much slowed down in Ubuntu 10.04 but all those major issues in Ubuntu 10.04 have been rectified now. The security settings are improving version after version in Ubuntu. I can find a lot of difference in the security in Ubuntu 8.10. The Ubuntu Software Center has undoubtedly become charming and more handy than ever, especially in the categorisation of the software. I should say, users had to face a bit of problem with the dependencies, broken links earlier; but now everything is managed so well by the Ubuntu software center, making it more user-friendly. Apart from this, the Instant messaging has added the new features of audio and voice chatting using Empathy Instant Messenger. I found that when the system files are being accessed, the system was taking so much time and was consuming large amount of CPU (almost 90% of CPU utilisation). This is the case when we open it in the GUI. The situation is however different when accessed through the Linux terminal. The authentication is a bit slow in Ubuntu 10.10 even though it was alright in Ubuntu 10.04.

Linux -- User Communication -- Part-3 -- news command

The system administrator is the sole person who can make news under the Linux. He types the information which he wants everyone on the network to know of in different files in /var/lib/sysnews directory. 

Whenever we log in if any fresh news has come in since we logged out last time then a message is displayed on our terminal saying, news: appeal rally where appeal and rally are the names of files in which the news items are available. We may either choose to ignore it, or if any news item interests us we may decide to pursue the same.

• First, we can look at the names of the news articles by the command news with -n option. Similarly, to know the number of unread news articles that are present in the /var/lib/sysnews directory, we use the command news with -s option. If you try news -s after you have gone through all the news items it promtly displays the message "NEWS: 0 news articles".

• The command without any options would yield the list of unread news articles one after another.

• At the same time, the user can pursue only a particular news article  from several items by specifying the article name after the command. For example, if you want to pursue the article named appeal, then you can run the command at the prompt as news appeal. 

• If the user decided to pursue all the news articles (read and unread), then the option -a has to be used with the command.

Linux -- User Communication -- Part-2 -- wall command

The write command is used for communication between two users connected to a network. However, if a user wants to send a message to everyone in the network; then the wall command will be used. The command is mostly used by the administrators for purposes such as the situation where the Unix/Linux system will be shut down in 10 minutes. He does so using wall. After giving the entire message, Ctrl - D must be pressed. The default behaviour of wall command is as shown in the below figure:

Another important thing to note about this command is that it writes to all the terminals irrespective of whether the users have given write permission to their terminals or not, as important messages are often posted using the wall.

Thus, this command is used to broadcast a message to everyone on the network and the necessary message is written onto the terminals of all the users.

A variation of wall would be to broadcast the contents in a file to all the terminals. This is done by the command given as: "wall < [file-name]". In this case, Ctrl-D need not be pressed. This is shown in the below figure:

To know about the next part of the Linux user communication, click here.

Linux -- User Communication -- Part-1 -- write command

The communication between/among different users in Linux systems connected in a network is actually just as simple as running some commands. A direct application of a network system, communication is handled expertly by Unix. The commands used for such a communication are as follows:

1. write
2. wall
3. news
4. mail

The "write" command:

The write command can be used by any user to write something on someone else's terminal, provided the recipient of the message permits communication. There are two pre-requisites for a smooth write operation:

• The recipient must be logged in, else an error message is inevitable.
• The recipient must have given permission for messages to reach his or her terminal.

If you do not want the messages to be posted on your terminal, just type the command: mesg n. But, by default the terminal allows messages to be posted on it. To know if the messages can be posted on your terminal or not, just type the command mesg. If the command returns "is y", then messages can be posted on your terminal, otherwise they cannot be posted. Before using the write command, it is a good idea to first ascertain who all are logged in and who allow messages to their terminals.

finger is one command that tells you which users are connected and which, if any can receive messages. It displays a list of all those who have logged in and places a * next to those terminals where mesg is set to n.

Another command that may be used for this purpose is who -T. The command who lists all the users who are currently logged in. When used with -T option, it places a '+' next to users who have allowed messages and a '-' sign beside others.

Now, the default behaviour of write command is as shown below. The first screen-shot is the terminal on the sender side and the second on the receiver side.

Variations of write:

• Writing to somebody who has set mesg to n on his terminal. The permission gets denied on such occasions. However, if the sender has mesg set to n and the receiver has mesg set to y then the reply to the message is not possible.

• A user logged in at more than one terminal and you want to send a message only to one terminal. The terminal specified in the command will be sent a message simply. If we do not mention the terminal to which the message should be sent, then the write command comes up with a smart solution in case of confusion. In all the above screen-shots the user is logged in at more than one place. For example, write user tty9 writes to the terminal tty9 of user-name user.

To know about the next part in Linux user communication to know the wall command, click here.

Linux terminal - Mathematics

Important mathematical calculations can be done by using the Calculator application available with the Linux applications. But these calculations and can be made by the following commands in the terminal:

1. bc
2. expr
3. factor
4. units

1. The "bc" command:
The programmable calculator called bc gets you into the calculator mode, and the $ prompt disappears. The command gives almost all the basic mathematics calculations. The input  to this calculator is taken line by line. Enter an expression and the result supplied in the next line. The inputs and results are self-explanatory. Typing "quit" gets you out of the calculator mode and ends your tryst with bc. The basic mathematical calculations can done using bc command as follows:

One of the useful features of bc is that of a base conversion. The variables ibase and obase are set such that ibase gives the base of the input and obase gives the radix or base of the output number. As shown in the figure below, the number is given in base 10 and the input is converted into base 2.

In addition, bc also supports functions like sqrt, cosine, sine, tangent etc., The trigonometric functions sine and cosine ( s() and c() respectively)would work only when the bc command is used with the -l option. The trigonometric functions expect their arguments in radians not in degrees.

A for loop can also be run in the calculator mode as shown below.

2. The "expr" command:
In addition to bc, the expr command is used for evaluating basic mathematical calculations dealing with only integers. The expr command cannot perform calculations on data other than integers. The operators must be surrounded on both sides by a space. When using * operator, use the backslash ( \ ) for the purpose of escape-sequencing since * operator is a meta-character.

3. The "factor" command:
The factor command takes as input an integer and gives the output all the prime factors of the input; each one is printed the proper number of times. To end it, press Ctrl - D. The command factor when used with the argument as the input, it returns all the prime factors of that number.

4. The "units" command:

The units command is another handy utility, which converts quantities expressed in various standard scales to their equivalents in other scales. It works interactively in this fashion:

Controlling the system while you are on Ubuntu

Any Windows user would suggest to hit Ctrl + Alt + Del which opens the Windows Task manager when an application becomes unresponsive. This manager contains the information of the running tasks, processes, networking and so on.

Similarly, in Ubuntu also we have such a manager which gives the details of various aspects like processes, networking etc., In Ubuntu, it is called "System Monitor". When an application becomes unresponsive in Ubuntu, then I would suggest you to use one of these methods:

1. Goto System -> Administration -> System Monitor and kill the process which is unresponsive.
2. Open Application -> Accessories -> Terminal and type "killall " and you are done with it.
3. Use "Force Quit" applet.