GNU Parallel Tutorial

This tutorial shows off much of GNU parallel‘s functionality. The tutorial is meant to learn the options in GNU parallel. The tutorial is not to show realistic examples from the real world.

Shell tool for executing jobs in parallel

ifconfig vs ip: What’s Difference and Comparing Network Configuration

Linux based distributions have featured set of commands which provide way to configure networking in easy and powerful way through command-line. These set of commands are available from net-tools package which has been there for a long time on almost all distributions, and includes commands like: ifconfig, route, nameif, iwconfig, iptunnel, netstat, arp.

These commands are just about sufficient in configuring the network in a way any novice or an expert Linux user would want, but due to advancement in Linux kernel over past years and unmaintainable of this packaged set of commands, they are getting deprecated and a more powerful alternative which has ability to replace all of these commands is emerging.

This alternative has also been there for quite some time now and is much more powerful than any of these commands. Rest of sections would highlight this alternative and compare it with one of the command from net-tools package i.e. ifconfig.

ifconfig vs ip: What’s Difference and Comparing Network Configuration

Python 3 RPMs are now available for RHEL/CentOS 6/7

“Python 3 is a new version of the language that is incompatible with the 2.x
line of releases. The language is mostly the same, but many details, especially
how built-in objects like dictionaries and strings work, have changed
considerably, and a lot of deprecated features have finally been removed…”

CentOS 7 with VirtualBox

To install VirtualBox Guest Additions on a CentOS 7 guest run this as root:

rpm -Uvh;
yum -y install dkms kernel-devel-$(uname -r) kernel-headers-$(uname -r);
mount -o loop VBoxGuestAdditions_4.3.14.iso /media/;

To install VirtualBox on a CentOS 7 host run these as root:

rpm -Uvh;
yum -y install dkms kernel-devel-$(uname -r) kernel-headers-$(uname -r);
yum -y localinstall;

How to add a new package to RHSCL perl516 for RHEL

“The Red Hat Software Collection (RHSCL) perl516 contains only a part of the packages which are packaged in RHEL or Fedora. It is not hard to add a new package to RHSCL. The following steps show how to convert a conventional spec file into a Software Collection spec file. The SCL spec file can then be used in both the conventional package and the Software Collection. We will use perl-Pod-Perldoc is used for an example…”