Feb. 3, 2011, 7:55 a.m.
posted by spooned
Files, Directories, and the Root of All Things
There's a saying in the Linux world that "everything is a file" (a comment attributed to Ken Thompson, the developer of UNIX). That includes directories. Directories are just files with lists of files inside them. All these files and directories are organized into a hierarchical file system, starting from the root directory and branching out.
The root directory (referred to as slash, or /) is actually aptly named. If you consider your file system as a tree's root system spreading out below the surface, you start to get an idea of just what things look like.
Under the root directory, you'll find folders called usr, bin, etc, tmp, and so on. Open up Konqueror by clicking on the icon in your taskbar that has a house in front of a folder. This brings up Konqueror in file manager mode (remember that Konqueror is also a Web browser). If your navigation panel isn't up (Konqueror's left side panel), press <F9> to open it (Figure). To either the right or left of the navigation panel (this is all configurable, remember), you'll see a row of tabs. Click on the root directory tab, the one that looks like a small folder. Here's a hint: If you move your mouse over the tabs and pause, a tooltip will pop up to let you know you are in the right place. When the file system tree appears (over on the left side), click on the top folder, Root Directory, and then look at the names of those folders.
Konqueror's file manager view with navigation panel (left) open.
These are all system directories, and they will contain all the programs that make your Linux system run, including documentation, devices, and device drivers. For the most part, you aren't going to be touching these files. Accidentally changing things around in this part of your system probably isn't a good thing, which is why everyone logs in with his or her own account.
One of the directories under the root is called home, and inside that directory you'll discover other directories, one for each login name on your system. These are the individual home directories, where you'll find your personal files and directories. If you want to store personal documents, music files, or pictures, this is the place. Once in Konqueror, you can jump to your home directory by clicking the house icon or clicking Go on the menu bar and selecting Home URL. This is your $HOME.
Try this. Over on the left side of the tree view, you'll see a little plus sign beside the home directory. Click on the plus sign, and the tree view will expand to show your own personal directory. Notice that the plus sign has become a minus sign. If you click it again, the directory view collapses. With the home directory expanded, click on your personal directory. You should see a few items appear in the right side view, including one icon labeled Desktop. For an example, see Figure. On the left side, /dev is expanded, and the right side view shows the same directory collapsed.
Expanding and collapsing directories.
Before you do anything else, I want you do look down in your taskbar, at the bottom of the screen. Do you see the desktop icon there, just to the right of the big K? It looks like a desktop blotter with a lamp above it. Move your mouse cursor over it, and the tooltip will display Show Desktop. Click it, and your desktop appears, free of windows. Click it again, and everything returns to normal.
I am having you do this because I want you to take note of what icons are on your desktop. Now go back to your Konqueror session and click on the Desktop icon in the right (or main) window. All the icons on your desktop show up there. Why is that, you ask? Because even those icons on your desktop are files or directories. Cool? Let's move on.
Directories (and subdirectories) will usually show up as folders, although this isn't a hard-and-fast rule because you can customize this. Nevertheless, some directories have different icons right from the start—the Desktop icon you just visited and the Trash can being two notables.