3.2.2. Absolute and relative paths

A path, which is the way you need to follow in the tree structure to reach a given file, can be described as starting from the trunk of the tree (the / or root directory). In that case, the path starts with a slash and is called an absolute path, since there can be no mistake: only one file on the system can comply.

In the other case, the path doesn't start with a slash and confusion is possible between ~/bin/wc (in the user's home directory) and bin/wc in /usr, from the previous example. Paths that don't start with a slash are always relative.

In relative paths we also use the . and .. indications for the current and the parent directory. A couple of practical examples:

• When you want to compile source code, the installation documentation often instructs you to run the command ./configure, which runs the configure program located in the current directory (that came with the new code), as opposed to running another configure program elsewhere on the system.

• In HTML files, relative paths are often used to make a set of pages easily movable to another place:

  <img alt="Garden with trees" src="../images/garden.jpg">

• Notice the difference one more time:

  theo:~> ls /mp3 ls: /mp3: No such file or directory theo:~>ls mp3/ oriental/ pop/ sixties/