cd – Change Directory

The cd command stands for change directory and is used (case-sensitive!) to change to a specified directory or subdirectory. It is a shell builtin command, essential for navigating the filesystem.

Syntax

cd [OPTION] DIRECTORY

If no directory is specified, cd changes to the user’s home directory.

Options

Option	Description
`-L`	Follow the logical directory structure (default behavior)
`-P`	Follow the physical directory structure (resolves symlinks)

These options mostly affect behavior when symbolic links are involved. In everyday use, cd without options uses the logical path (-L).

Practical Examples

1. Change to the home directory

cd ~

or simply

cd

Both commands will take you to your home directory. The home directory is defined by the environment variable $HOME and is not necessarily /home/username.

2. Change to an absolute directory

cd /usr/local

Changes directly to /usr/local.

3. Change to a relative directory (subdirectory)

cd bin

If your current directory is /usr/local, this moves into /usr/local/bin.

4. Change to the parent directory

cd ..

Moves one directory up (to the parent directory).

5. Using physical path resolution

cd -P /path/to/symlinked/directory

Follows the actual physical directory structure, resolving symbolic links.

Tips

Use pwd after cd to print your current directory and verify navigation.
cd - switches to the previous directory you were in.
Tab completion often helps auto-complete directory names.
When scripting, using cd carefully can avoid errors related to unexpected directories.

Summary

The cd command is the most fundamental way to navigate the filesystem in the shell. It supports logical vs physical path navigation, but is most commonly used without any options to quickly move around directories.