How to Install New Versions of Octave on Enterprise Linux

This how-to is specifically for installing Octave 3.2.3 on CentOS 5.5 but should work on any recent version of RHEL or RHEL clones, with a few minor variations. The version of Octave to be installed depends on whichever version is in the Black Op Software repository.

Preliminary steps

To be able to install the octave package through Yum, the RPMForge and Black Op Software repositories need to be installed and it is recommended to remove the Extra Packages for Enterprise Linux repository and any installed packages from it as they are likely to conflict with the Black Op Software package. This is because the Black Op packages are built against the RPMForge packages which are compiled with different features than the ELEP packages.

Installing the RPMForge repository

This is paraphrased from the RPMForge wiki and the CentOS wiki.

1. Download the rpmforge-release package.

   • This one for i386 EL5

   • This one for x86_64 EL5

2. Install the repository GPG public key:

   rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt

3. Check the signature of the downloaded package with

   rpm -K rpmforge-release-0.5.1-1.el5.rf.*.rpm

4. Install the rpm using

   rpm -Uvh rpmforge-release-0.5.1-1.el5.rf.*.rpm

5. Edit /etc/yum.repos.d/rpmforge.repo and set

   enabled = 1

Installing the Black Op Software repository

This is paraphrased from the Black Op Software wiki.

1. Download the blackop-repo package from here.

   Note: there is only one package because it is architecture independent (noarch)

2. Install the Black Op Software GPG public key:

   rpm --import http://blackopsoft.com/el5/RPM-GPG-KEY-blackop

3. Check the signature of the downloaded package with

   rpm -K blackop-el5-repo-1.0-2.noarch.rpm

4. Install the rpm using

   rpm -Uvh blackop-el5-repo-1.0-2.noarch.rpm

5. If yum-priorities is installed, the priority of the blackop repository needs to be set fairly high, otherwise there will be conflicts between the base gnuplot package and the one provided by Black Op Software.

Installing the octave package and troubleshooting

This should now be as simple as running, as root,

yum install octave

If there are package conflicts or related errors, make sure that any of the involved packages are installed only from the rpmforge and blackop repositories. Try removing the problem packages and reinstalling them to make sure that they are coming from either the rpmforge or blackop repositories.

I Am Special: Cron Edition

I've been running Gentoo Linux for at least four years now. I used to use the vixie-cron daemon to run scheduled tasks like keeping installed software and a directory database up to date until I bought a new computer over a year ago. When I set up the new computer I decided to switch from vixie-cron to fcron because the machine is primarily a desktop system and fcron apparently is more suited to systems that aren't always on.

It wasn't long before I realized that my scheduled tasks were not running when they should. I did some cursory explorations at the time to figure out what was wrong. The daemon was starting up and running fine and the scripts were properly installed in the cron directories. I was busy with other things at the time and so I put solving the problem on the back burner until today when it finally bugged me enough that I wanted to fix it. I dug a little deeper and checked the system cron scheduling file (/etc/crontab) which is where I found this message:

# fcron || dcron:
# This is NOT the system crontab! fcron and dcron do not support a system crontab.
# to get /etc/cron.{hourly|daily|weekly|montly} working with fcron or dcron do
# crontab /etc/crontab
# as root.

Duh.