The understanding of pathnames is
critical to understanding file systems and is fundamental to
understanding UNIX or any other operating system. A pathname uniquely identifies a particular file or directory by
specifying its location. Pathnames are similar to a road map or a set
of directions that tells you how to get from one place in the
directory hierarchy to another. For instance, if you were giving
someone from another country directions on how to get to you, you
would have to specify where you live. The directories in a file system
can be compared to a country, state and city, etc.
If the earth were
like a hard disk with a file system, we would consider it the root of
the file system. If we wanted to identify the location of a guy named
Brad to tell someone where he lives, we would specify the pathname
until we got to Brad. We would use a fully qualified pathname so there
would be no doubt that we are talking about Brad of planet earth and
not some other planet.
Figure
shows the hierarchical relationship between the root directory and the
coffees subdirectory. The set of directories you must go through from
the root directory is the path name from the root directory through
several intermediate subdirectories to the coffees subdirectory. Every
file and directory in the file system has a pathname.
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