When learning shell script, a very common script which is given as a task in schools is to write a script to check if a string is a palindrome or not. I am presenting two solutions of this simple problem. A palindrome is a string whose reverse is same as the string itself. Like “madam” is a palindrome but “hello” is not
Latest Myth: Fedora Cannot run Shell Script
A lot of people running around asking for RedHat Linux, suddenly, and most of them at last getting pointed to me and getting disappointed. When asked why RedHat, and why not any one among the hundreds of other distros, I came to know a very important information: “Shell programming cannot be done in fedora”. It was very difficult to understand how this idea spread virally around the 3rd year honours Asutosh College students (a lot of them). The strangest part is even a shell program is run in front of the mass, they refuse to believe that Fedora actually can run shell script. It feels like someone going down to Sachin Tendulkar and telling “Hey man, you know nothing of cricket”.
Whatever it be it is better to get out of this myth and face the cruel reality : “Fedora CAN run shell programs” . Before comments to this post starts raining asking why, let me tell what I know and support my statement.
To run shell scripts you need basically the below three components:
- An OS kernel
- A shell
- The set of commands which will be used in the script
Now, in GNU+Linux systems we have the Linux kernel, The bash shell (some may have others as well), and the standard set of commands are the coreutilities. There are some more packages which contains some commands (programs) which are used.
Each of the above components are very basic and includes in all the GNU+Linux operating systems. Even an OS of size below 10MB can contain the components, which any one with proper knowledge can make for herself. Even before booting the Fedora or any GNU+Linux OS, the initial ramdisk image the initrd runs a long shell script, which configures the system and helps fedora or any GNU+Linux OS to boot.
Conclusion: Fedora can run shell scripts (Sachin can play cricket), provided the programmer knows shell scripting. (provided the bat is not a table tennis bat).
New Year 2010 GIMP Wallpaper
This time it is a new year wall paper, although i am late for it. This is also a simple wallpaper, no complex operations required. Again i have used the flame plugin and had the X effect. Follow the guide and see if you like it.
Christmas Wallpaper with GIMP
Hey it’s Christmas! I thought i should make a Christmas Special wallpaper, and started GIMP. And after 10 minutes it was ready. A very simple one with very least effects. I have described how i created the wallpaper in this post, hope you like it. Read the guide.
Floating point math operations in bash
When writing scripts in bash, sometimes we need to work with basic math functions. Like the trigonometric functions, square root, cube root, logarithms. Bash does not support floating point operations. This is where the problem is encountered, and we cannot write a math function of our own. There must be a way to do this, and yes. Bash supports redirections so we can feed the floating point computations and the math functions into some other program’s input who understands it. The program which can be used is the bc, which is an arbitrary precision calculator language. bc can do floating point operations, and also can do basic math functions. With bash and bc we can do the above. Continue reading to know how.
Pause and Break the Key
Yesterday in college I found an IBM keyboard with a broken Pause/Break key. Now why is this particular key broken, when It is rarely used? Almost instantly I realized, that the answer was written on the key, a previous user might have just followed what was written on the key.
CDlinux
In the world of minimalist GNU/Linux distributions, we introduce you to CDlinux, which originated in the People’s Republic of China, in 1999. Four years later, in 2003, the first public release, version 0.4.2, came out. The latest version 0.9.5, which was released on December 02, 2009, is a mere 62 MB.
CDlinux, or Compact Distro Linux, was primarily intended for systems administrators as a systems rescue tool. But it can also be used as a bare minimum portable desktop OS and as a customisable OS base. The default desktop environment is Xfce (currently 4.6.1) with the Thunar file manager, thus ensuring CDlinux cuts out the fat. The whole distro loads on the RAM, so the access is rapid. The official edition’s RAM requirement is only 64 MB. CDlinux is capable of booting from CD/DVD and HDD. It also supports USB and IEEE1394 interfaces for booting. Continue reading to know more about CDlinux
Continue reading “CDlinux”
CD Tray Open/Close infinite loop
Just feel the annoyance and irritation when the CD tray of your computer opens and closes, opens and closes, again and again, again and again, and does not stop until you shut down the computer. We will be writing a tiny shell script with which we would do the above stuff. Although this is very cruel if you apply this to some one, then please be sure to fix it before he/she shoots you with a 50 caliber rifle. So keep on reading to know how to make the simple script to make an infinite CD-ROM tray open close loop in GNU+Linux
Beginners Guide to GCC
GCC is the default compiler in the GNU+Linux systems, and is used to compile small applications, big softwares, and the kernel. Often beginners are overwhelmed with the amount of information provided in the gcc manual. This tutorial highlights the most useful commands and describes how to use them, how to read warnings and errors from the compiler output and compile the C Language sourcecodes with gcc. This tutorial does not cover advanced options and topics, in depth details are avoided. This tutorial will give the basic idea, and after reading this i hope that the manual pages would be easier to read.
GIMP Glassy Text Wallpaper
Playing with GIMP is never boring, every time you do some experiment you come to know of some cool effect. The best part is the filters, which if applied properly, can produce jaw dropping effects. While experimenting with GIMP i came to know that how easily glassy texts could be created with gimp. Although i am not a image maker, or a GIMP expert, i will try my best to describe this process. I have broken down this process in some sections, each one describing how to make each image effect component. Let’s start.
Phoxis 