Usually you change the default runlevel by editing /etc/inittab. However, sometimes you boot into runlevel 3 (e.g. by selecting safe mode from the grub menu) and then want to change to runlevel 5. This you accomplish on the fly with the command: telinit 5
Today I installed the latest in file sharing: BitTorrent. Was a bit cumbersome as I first had to install wxPython. And to install wxPython, I needed wxGTK. There is apparently a RedHat9 RPM around, but the download site was down all day long, so I got the source wxPythonSrc-2.4.1.2.tar.gz from sourceforge. After that I tried to download the RedHat9 CDs as I need a clean Linux install to test Adobe Acrobat 5.0.7 and Crossover Office (Acrobat 5 crashes immediately after start on my RedHat9 system and the Crossocer Office seems also to be somehow compromised by excess fiddeling).
I have been using is for years, but hardly have used its "advanced" options. That is:ls -t to sort the content of the directory according to modification date. ls -d to display the directories and not their contents. ls -alh lists the complete content of the directory in long, human-readable form (that means file sizes are given in B, K, M or G and not in bytes).