Use the OR operator in grep to search for words and phrases

grep is a very powerful command-line search program in the Linux world. In this article, I will cover how to use OR in the grep command t...Read more »

Root edit a file using emacs in the same session

We know that we should always log in using our regular non-root account, and only sudo in when necessary to do things that only root can d...Read more »

Delete Windows/DOS carriage return characters from text files

Different operating system may use different characters to indicate the line break. Unix/Linux uses a single Line Feed (LF) character as lin...Read more »

upgrading zlib

I have to upgrade my zlib to version 1.2.3 to upgrade clamav 0.93. If you have recent version (after July 18,2005), you might have it instal...Read more »

Run ifconfig as non-root user for read-only access to network interfaces

It is a frequent scenario that you are logged in to the console of a Linux system, and you need to know its IP address. If you are the root ...Read more »

Ping or nmap to identify machines on the LAN

You can use ping or nmap to find out what machines are currently on the local network. The first method involves pinging the LAN broadcast...Read more »

How to indent lines in text files using sed, awk, perl

Suppose I have a text file named input.txt , and I want to indent each line in the file by 5 spaces. $ cat input.txt 12 34 56 78 The followi...Read more »

How to convert text files to all upper or lower case

How can you convert a text file to all lower case or all upper case? As usual, in Linux, there are more than 1 way to accomplish a task. To ...Read more »

How to prevent Linux man pages from clearing after you quit reading

Man pages are excellent resources for learning the specifics of a Linux command. After all, who can remember all the nitty gritty of a com...Read more »

Installing CentOS 5.1

Hi all, I am installing CentOS 5.1 to a machine at my friend's office. I had to download 7 ISOs beforehand but it needs only 5 CDs for c...Read more »

bash quicksand 2: Quotes needed in string tests

This is part 2 of the bash quicksand series. Part 1 is about whitespaces in variable assignment . When you write bash shell scripts, you wa...Read more »

How to Display Routing Table

To display the kernel routing table, you can use any of the following methods: route $ sudo route -n Kernel IP routing table Destination ...Read more »

Compare Directories using Diff in Linux

To compare 2 files, we use the diff command. How do we compare 2 directories? Specifically, we want to know what files/subdirectories are ...Read more »

Catatan upgrade Gutsy Gibbon menjadi Hardy Heron

Sudah seminggu sejak Hardy Heron dirilis, dan sudah seminggu ini pula saya mengupgrade Gutsy Gibbon di laptop saya menjadi Hardy. Dengan ko...Read more »