Technology Insights

Install ATRPMS Yum Repository On CentOS Linux

The ATrpms repository provides many bleeding edge software packages so if you have a development server where you install new apps this repo can be very useful. The instructions are not 100% clear about how to install this repository on CentOS Linux which would also be the same on RedHat Linux but not on Fedora Linux. Anyhow the example used on the ATrpms site relates to Fedora so the repo file needs to be modified to work on CentOS as noted below.

Technology Insights

Change vi Defaults To Not Display Line Numbers When Editing Files On Linux

Recently I was contracted to do some work for a new client that had around 25 CentOS Linux and Ubuntu Linux servers. The client needed various system administration tasks completed such as updating the servers, modifying a couple scripts that performed automated tasks, and a couple other basic tasks. I typically use vi to modify scripts or text files on Linux servers so when I started to perform my tasks I started getting annoyed as the vi default configuration included the line numbers which makes it a pain to copy/paste from the files you are editing. You can obviously turn off the line number display by typing “:” followed by “set nonu” (both without the quotes) however that does get old. Use the information below to change the default vi configuration so line numbers no longer display by default.

Technology Errors

vBulletin: You Specified a Tag That Was Too Long. A Tag Can Only be 25 Characters

As many people know I am one of the administrators of the Backtrack-Linux forums. We generally do not have to many issues but today I had someone complaining that when posting code they were not able to use more than 25 characters. This is a issue since we encourage our users to use the tags for there posts since it makes adding code much neater and easier to read & copy/paste. Below I will describe how to fix the error.

Technology Errors

Linux -bash: which: command not found

Typically the “which” command is installed by default though depending on what Linux distribution and what packages you decided to install there is a possibility the command is not installed. Installing which is easy on any distribution as the package is literally just called “which”. Below is a brief explanation of the error you could get if which is not installed and information on how to install the which package using the yum package manager on CentOS.

Technology Errors

Yum Error – ImportError: No module named yummain

You may see an error like the below when attempting to see if a certain package is installed using the yum package manager. Yum is the default package manager on RedHat Linux and CentOS Linux. Using the “yum list *SOMETEXT*” command will list all packages that contain “sometext” or you could use “yum list sometext” which will list a package specifically called “sometext”. Below you can see an attempt to list the “git” package on a CentOS server however an error was returned.