There are hundreds of commands and utilities plus thousands of support files in a normal Linux installation. Very few people I have met know what they all do. As a matter of fact, I don’t know anyone who knows what they all do. Some are obvious and we use them everyday, such as date. Others are not so obvious and I have never met anyone who has used them. Despite their overwhelming number and often cryptic names and even more cryptic options, many commands are very useful and powerful.

I have often encountered users, as well as system administrators, who combine many of these commands into something fairly complicated. The only real problem is that there is often a single command that would do all of this for them.

In this section, we are going to cover some of the more common commands. I am basing my choice on a couple of things. First, I am going to cover those commands that I personally use on a regular basis. These commands are those that I use to do things I need to do, or those that I use to help end users get done what they need to. Next, I will discuss the Linux system itself. There are dozens of scripts scattered all through the system that contain many of these commands. By talking about them here, you will be in a better position to understand existing scripts should you need to expand or troubleshoot them.

Because utilities are usually part of some larger process (such as installing a new hard disk or adding a new user), I am not going to talk about them here. I will get to the more common utilities as we move along. However, to whet your appetite, here is a list of programs used when working with files.