Technology Insights

Install Ruby 1.8.6 On CentOS 5.X Using A Yum Repository

The latest available Ruby version in the default CentOS repositories is currently Ruby version 1.8.5. Many packages in the default CentOS repos are notorious for lagging way behind what versions of the packages are currently available. Even though Ruby 1.8.7 and Ruby 1.9.X are available I simply needed to get Ruby 1.8.6 installed for a project I was working on so I used the information below to install Ruby 1.8.6 on CentOS Linux using the Yum Package Manager.

Technology Errors

CentOS Linux: Can’t install RMagick 2.7.0. Can’t find Magick-config

While prepping a development server earlier this afternoon I ran into an issue installing the rmagick gem. This was one of a list of 30 or so gems required by a Ruby project that was being installed onto the development server. I thought initially something else was wrong because I had run into this issue before but I thought I had installed ImageMagick via the yum package manager to resolve the problem. Anyhow after verifying ImageMagick was installed I still had the same issue on the development CentOS Linux server. Below I describe the error in detail along with what was done to resolve the issue.

Technology Insights

How to Batch Resize Image from Linux Shell with ImageMagick

ImageMagick is a really cool product. Not only is it open source but its very powerful tool. My goal was to figure out how to batch resize images while keeping one side 640 pixels wide. I ended up using ImageMagick’s mogrify by issuing the command below at my CentOS shell prompt.

mogrify -resize x640 *.jpg


mogrify -resize 640 *.jpg

Depending on which side you want to be 640 pixels. If you would like for image magic to make the largest side 640 and constrain the proportions use the following command.

Technology Insights

Linux Commands to Install ImageMagick and RMagick

This is what I had to do to get it to work on CentOS 5. For some reason, FreeType would not work with yum so I built it from scratch. I’m not sure if the all the “yum install”s were needed, but I did it anyway.

#yum install freetype — did not work

cd /usr/local/src


tar xvzf freetype-2.3.5.tar.gz



make install