Are there times of the night that you find yourself adjusting your screen brightness lower, either to help your eyes or not bother someone else? It can be annoying have to tweak brightness settings all of the time. We'll show you how to set your brightness automatically during the night. Read on.

To start, you need to have a laptop or a display that supports software brightness configuration. You'll also need to make sure that your GNOME brightness settings are working. (KDE fan? Submit a relevant article.) Also, take note that if your system is not on when brightness settings change, they will not be updated.

Now, pop open a terminal to edit your crontab:

crontab -e

Now you'll want to add some time and brightness settings. Use this as a template:

0 22 * * * gconftool-2 --type int --set /apps/gnome-power-manager/backlight/brightness_ac 10
0 7 * * * gconftool-2 --type int --set /apps/gnome-power-manager/backlight/brightness_ac 100

The first line will set the brightness value to 10% at 22:00; the second sets it to full brightness at 07:00. Note that these are not hardware brightness values, but power manager values that scale from 0 to 100. You can add as many lines as you want. If you're proficient in your crontab syntax, then you can even use settings that only apply on weekends or weekdays.

We all like to learn a little bit about our computers and how they stack up against others. Even if not, the information might be valuable to others trying to diagnose a problem with your machine. There are many ways to discover information about your hardware in Linux, but none of them have come close to the ease-of-use of HardInfo (install).

HardInfo takes everything it can find about your system and presents it in an organized fashion. There’s no need to dig through the output of lspci or run a few commands to find out some network statistics; it’s all right there in front of you.

One key feature that makes HardInfo valuable is its ability to quickly generate a system report. This can be very useful to bug triagers, developers, or your laptop’s eBay listing.

Finally, HardInfo is a great tool to use to rank your system against other machines with various benchmarks, which can tell you if your machine is running at full speed or if something is going terribly wrong. These are also included in the generated reports.

Overall: great tool, easy to use, useful for everyone. Give it a try.

If you followed my recent video tutorial on enabling Ubuntu/GNOME’s Tracker search tool, you should now be enjoying the ability to search the files on your system.

During a recent upgrade to Ubuntu 9.04, which was recently released, I found that the Tracker search tool index had become corrupted. I tried to tell Tracker to rebuild the index, but experienced some weird issues.

In this quick tip, I’ll show you how to avoid this and other issues by deleting Tracker’s index and cache manually, so that it can start ‘from scratch’. Note that if you are having issues with tracker, it is worth trying to rebuild the index from the graphical interface first. This tip is a last resort if you need to clear everything out from scratch and start it again.

Tracker’s Files

According to the documentation, Tracker stores its files in the following locations:

• Configuration Files – ~/.config/tracker/tracker.cfg
• Data Files – ~/.local/share/tracker
• Index Cache – ~/.cache/tracker

If you’re happy with the settings you have, you may want to leave the configuration file intact, and just wipe out the data files and index cache.

Quit Tracker and Delete the Files

First of all, you need to go ahead and quit the Tracker application in the system tray.

Next, you must quit all processes of both trackerd and tracker-indexer, so open up a terminal and run these commands:

And finally, carefully delete the files listed above (excluding the config file, if you don’t think you need to clear that out as well).

So to recap, go ahead and delete the folders:

• ~/.local/share/tracker
• ~/.cache/tracker

and if you wish, the config files:

• ~/.config/tracker/tracker.cfg
• ~/.config/tracker/tracker-applet.cfg

To restart Tracker, I recommend that you log out and log back in so that trackerd and the system tray applet both restart properly. You should then be able to reconfigure it from the beginning as detailed in the original tutorial.

And that should be it – Tracker should rebuild itself from scratch. Useful to know for if things go wrong!