The GNU Project has provided dozens of useful utilities that you can find on almost every major Linux system, but many new Linux users have no idea where to start to learn these handy utilities. In this tutorial, I'll cover a few of the utilities that you can use to measure file system usage, verify the size of files, and take a peek into larger text files like Apache logs. Virtually ever major Linux distro comes with these utilities installed. Some distros designed for resource constrained systems might make use of BusyBox, which includes replacements for most of the GNU utilities. In that case, you should have the same utilities, but they may lack features found in the GNU utils or have slightly different options, etc. However, if you're using the mainstream distros like Fedora, Debian, Ubuntu, openSUSE, Mandriva, Slackware, etc., you should have the standard utils from the start.