3 - Weber State University

88 Chapter 3 Exploring Linux Filesystems
An understanding of the structure and commands surrounding the Linux filesystem
is essential for effectively using Linux to manipulate data. In the first part of this chapter,
you explore the Linux filesystem hierarchy by changing your position in the filesystem tree
and listing filenames of various types. Next, you examine the shell wildcard metacharacters
used to specify multiple filenames as well as view the contents of files using standard Linux
commands. You then learn about the regular expression metacharacters used when searching
for text within files, and are introduced to the vi editor and its equivalents.
The Linux Directory Structure
Fundamental to using the Linux operating system is an understanding of how Linux stores
files on the hard drive. Typical Linux systems could have thousands of data and program
files on the hard drive; thus, a structure that organizes those files is necessary to make it easier
to find and manipulate data and run programs. Recall from the previous chapter that Linux
uses a logical directory tree to organize files into different directories (also known as folders).
When a user stores files in a certain directory, they are physically stored in the filesystem of a
certain partition on a hard disk inside the computer. Most people are familiar with the Windows
operating system directory tree structure as depicted in Figure 3-1. Each filesystem on a hard
drive partition is referred to by a drive letter (such as C: or D:) and has a root directory (indicated
by the \ character) containing subdirectories that together form a hierarchical tree.
It is important to describe directories in the directory tree properly; the absolute pathname to a
file or directory is the full pathname of a certain file or directory starting from the root directory.
In Figure 3-1, the absolute pathname for the color directory is C:\windows\color, and the absolute
pathname for the sue directory is D:\home\sue. In other words, we refer to C:\windows\color as
the color directory below the windows directory below the root of the C drive. Similarly, we
refer to D:\home\sue as the sue directory below the home directory below the root of the D drive.
Linux uses a similar directory structure, but with no drive letters. The structure contains a
single root (referred to using the / character), with different filesystems on hard drive partitions
mounted (or attached) to different directories on this directory tree. The directories that
each filesystem is mounted to are transparent to the user. An example of a sample Linux
directory tree equivalent to the Windows sample directory tree shown in Figure 3-1 is depicted
in Figure 3-2. Note that the subdirectory named “root” in Figure 3-2 is different from the root (/)
directory. You’ll learn more about the root subdirectory in the next section.
In Figure 3-2, the absolute pathname for the color directory is /windows/color, and the absolute
pathname for the sue directory is /home/sue. In other words, we refer to the /windows/
system
C:\ D:\
windows root
color
Figure 3-1 The Windows filesystem structure
Source: Course Technology/Cengage Learning
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