Author Archives: LinuxUser

Cool tips to change Ubuntu command line prompt colour

I have recently installed Ubuntu 12.04 LTS on my laptop. The first surprise that I got was in the form of the new unity GUI. Anyway, that’s a different story. Other thing that bothered me after sometime was the Ubuntu command line prompt colour. The concern was that while analysing problems where I had to go through lots of data on command line, I was many time lost as to where the output began.
Continue reading

Intrusion detection system – Part I (The basics)

In this insecure world of internet where even the governments are struggling against intrusions then there has to be a safeguard that can help companies and individuals to strengthen the defence and retaliation capabilities of their computers. So, In this article we will discuss the basics of Intrusion detection systems or IDS.

Continue reading

Introduction to Linux IPtables

Linux today is the fastest growing operating system that is replacing it’s competitors in almost every sphere of technology field. The major reason for this is the simplicity and robustness of this operating system. Besides, there is another quality in Linux that makes it favourite of many. This quality is the seamless customization that can be done with every aspect of this OS. One of the very important aspect is the Linux security. There are many protections and inbuilt security mechanisms that Linux incorporates in the name of system and network security. One of the inbuilt security mechanism is the Linux firewall. Linux provides a very flexible and powerful mechanism to customize the firewall. This mechanism is the Linux IPtables.
Continue reading

Ubuntu 12.04 installation issue: Ubiquity installer crashes

The other day I was installing Ubuntu 12.04 LTS from a boot-able pen drive. Everything went smooth as Ubuntu was easily able to detect that my system is dual booted with Microsoft Windows XP Professional. It suggested me to overwrite or upgrade the existing Ubuntu (Linux Mint that I was using earlier). I went ahead with overwriting the existing Linux mint.
Continue reading

The concept of extern variables in C

Most of the C projects are not single file projects. The code is spread over tens or hundreds of files. Now suppose there is a situation where you have declared and defined a variable in one file (say file1) and want to use the same variable in other file (say file2) by just telling the compiler that this variable is already defined somewhere else. What would you do? Well, this can be done through the concept of extern variables in c.
Continue reading

Delete a directory using Linux rmdir function

In our last article on unlink() function here, we discussed how this function can be used to delete files. Also, this function has a limitation that it cannot be used to delete directories. Here in this article, we will discuss the Linux rmdir function. As the name suggests this function is used to delete directories in Linux.
Continue reading