Q. I need to sort data from a log file but there are too many
duplicate lines. How do I remove all duplicate lines from a text
file under GNU/Linux?   Q. How do I find out my IP address
assigned to eth0 or ra0 interface using perl? A. If you need to
know the IP address of the UNIX / Linux machine you are running
on, use the following perl one liner. Perl don’t have any
inbuilt facility but combination of ifconfig command ans shell
[…]   Q. I’m using CentOS on 64 bit Linux. How do I find out rpm
package architecture before installation such as i386 or x86_64
bit? A. Almost each rpm package has i386 or x86_64 added to file
extension. However some time you may see filename such as file-
version.rpm. You can list all installed rpm packages with […]  {
1 comment }  How do I remove all spaces from string using shell
scripts? I’ve var=”This is a test”, and I’d like to remove all
spaces.   How do I use tar command over secure ssh session?