Change Directory (cd <pathname>)

To change your working directory, use the cd command. To do this, type cd followed by the pathname of the desired working directory. A pathname is the route we take along the branches of the tree to get to the directory we want. Pathnames can be specified in one of two different ways;

• Absolute pathnames
• Relative pathnames

Absolute Pathnames

An absolute pathname begins with the root directory and follows the tree branch by branch until the path to the desired directory or file is completed. For example, there is a directory on your system in which most of your system's programs are installed. The pathname of the directory is /usr/bin. This means from the root directory (represented by the leading slash in the pathname) there is a directory called "usr" which contains a directory called "bin".

[robin@pc-name] $ cd /usr/bin
[robin@pc-name bin] $ pwd
/usr/bin
[robin@pc-name bin] $ ls
....... listing of many files ....

Now we can see that we have changed the current working directory to /usr/bin and that it is full of files. Notice how the shell prompt has changed? As a convenience, it is usually set up to automatically display the name of the working directory.

Relative Pathnames

Where an absolute pathname starts from the root directory and leads to its destination, a relative pathname starts from the working directory.

[robin@pc-name usr] $ pwd
/usr
[robin@pc-name usr] $ cd bin
[robin@pc-name bin] $ pwd
/usr/bin

Now we have changed the working directory from /usr to /usr/bin.

Special symbols

Some special symbols represent relative positions in the file system tree. These special symbols are . (dot) and .. (dot dot).

• The . symbol refers to the working directory.
• The .. symbol refers to the working directory's parent directory.
• The ~ symbol refers to the user home directory.
• The - symbol refers to the previous working directory.

Navigating Up ( .. )

Once inside a directory, it can be useful to be able to navigate back up a directory. One way to do this would be to call cd giving it the full path to the directory you want to go. Another way to accomplish the task of moving up to the parenet directory is to use the special path ...

$ cd ..

Telling cd to navigate to .. will navigate to the parent directory of the current directory.

Navigating to the Home Directory

When you are in a directory and want to navigate back to your home directory, you can call cd without any argument.

$ cd
$ pwd
/Users/robin

Alternative, you can cd the ~.

$ cd ~

Summary of the helpful shortcuts

Shortcut	Result
cd	Changes the working directory to your home directory.
cd ~	Changes the working directory to your home directory.
cd -	Changes the working directory to the previous working directory.
cd ~user_name	Changes the working directory to the home directory of user_name. For example, cd ~bob will change the directory to the home directory of user “bob”