Why not use YUM?

There's no easy way to detect that yum has appropriate repositories setup on older RHEL/CentOS versions. So, if you have up2date, that's what gets used, and if not it tries yum. If you don't want to use up2date for the installation you'll have to remove it. But it doesn't hurt anything to use it.

The install script used to display what was happening during the installation, but then the log didn't get enough information for me to debug problems. Shell scripts can't check return values, print to the screen, and write to a log, and so I chose the path of least evil. (The reason for this problem is that if you use tee, you get the return value of tee rather than the command being run.)

As soon as the new theme is finished and released, I plan to rewrite the whole install script in Perl. I will then be able to fork when I need independent commands to execute with logging, error detection and progress reporting. I somehow though that writing it in bash would be faster and cleaner, since the majority of work is running various commands...but then I ran into all of the limitations of shell scripts. (I'm sure I could resolve this issue in bash, if I poked at it long enough, but there are another half dozen problems with bash that will be solved by a port to a more complete language. Since we need Perl for everything else, anyway, it's the natural choice.)