Pathnames specify the location of a
directory or file in the directory structure.
In order to navigate the directory structure, it is necessary to have
an understanding of pathnames. There are two types of pathnames used
with UNIX and other operating systems, absolute and relative. Either
method can be used at any time. An understanding of each is critical to understanding and navigating the file system.
Absolute Pathnames
An absolute pathname specifies a file or directory in relation to the
entire UNIX file hierarchy. The hierarchy begins at the / (root)
directory.
If you refer to a directory using its absolute pathname, you can
always be sure you will get to the correct directory since you always
have the common starting point of the root directory. Absolute
pathnames have the following characteristics:
- They always start at the root (/)
directory and list each directory along the path to the
destination file (or directory)
- They always use a slash (/)
between each directory name in the path to indicate different
directories
Relative Pathnames
A relative pathname describes the location of a file or directory as
it relates to the current directory or the directory you are currently
in.
If you are in a directory and you want to move down the directory
tree, it is not necessary to type the absolute pathname. You can just
type the path starting with the name of the next directory down in the
directory structure. If a pathname does not begin with a slash, it is
a relative pathname.
Relative pathnames are useful because they are usually shorter than
absolute pathnames. In order to use relative path names, you must know
what directory you are currently in since that is your starting point.
The directory you are in at any point can change so you must know
where you are in the directory tree or hierarchy. Absolute pathnames
are usually longer but they are consistent because you specify the
path from the root every time regardless of what directory you are
currently in.
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Interactive
Media Activity
(Flash,
25 kB)
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Pathnames
Exercise
Work through the media activity shown to demonstrate your
understanding of absolute and relative pathnames. Refer to the Class File Tree Structure by clicking the 'tree' button located on the Menu Bar
and enter the Absolute or
Relative pathname for the directory or file requested. Be sure to use forward slashes and note
that all directory, subdirectory and file names are case-sensitive.
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