The following is a list of variables you can use for both yum commands and yum configuration files.

Instead of killing the process in order to run dhclient to get a new lease, just release it. See? No need to kill it. Now you can ask for another lease.

You can list the contents of an rpm without installing it first. If you’re not going to build your own from source, you should at least check an rpm before installing it to see what it’s going to install.

With rpmbuild, you can make custom packages for any architecture, but what if there’s no difference between the architectures in what you’re building. If you’re copying around something like scripts, docs or other text files that have nothing to do with 32 vs 64 bit or endianness, it’s easier and more efficient to create a single noarch package and just keep one copy of it in a repository.

In udev rules, the %k, %b, %n variables are nice and all, but you can also use the variables you’re comparing and setting such as ID_FS_TYPE, KERNEL, SUBSYSTEM, PHYSDEVPATH, etc. When you run a command in a udev rule, there’s nothing stopping you from calling a shell and executing a few commands without actually calling a standalone script to do the dirty work. If you write out the array of environment variables from inside an external program, you can get a better understanding of just which part of the device discovery is matching your rule and getting processed.

I haven’t run into this fancy little kernel output before. While automating the writing of partition tables and file systems to removable storage devices, I thought i’d test the case of a read-only file system. This error comes from trying to write a partition label to /dev/sr1 which is the cdrom device. *** stack smashing detected ***: unknown terminated. backtrace and memory map…

Do letters show up when you hit the arrow keys in edit mode? If you like to use the arrow keys in vim/vi, you will quickly notice that Ubuntu appears broken. Welcome to vim compatibility mode. It’s just a setting that Ubuntu defaults to…

These packages are not available in the out-of-the-box configuration when you install Ubuntu 10.04. To get sun java packages such as sun-java6-jre or sun-java6-doc, you need to give yourself access to additional repositories… Now try searching for or installing one of those packages you were missing.

What would I do without the Linux shell? The sheer number of mouse clicks required to do this in Windows would result in instant and painful arthritis. For each Makefile in any child directory below pwd, It’s looking for a broken include string where the include was specified after the library and if it finds this case, it rewrites that part so it’s include/library. It’s basically the same thing done over and over for each include that might exist in any Makefile.

You used to be able to edit /etc/apt/apt.conf and assign a variable there, but not anymore. Set the http_proxy environment variable to your proxy and put it in your bashrc to make this setting persistent.