Overview

cd changes the current working directory. It affects where relative paths resolve.

Syntax

cd [directory]

Arguments

• directory: Target directory. Defaults to $HOME.

Options Table

Examples

cd /var/log
cd -
cd ~/projects

Real-world Usage

Use cd - to bounce between two working directories during incident response.

Common Mistakes

• Using relative paths in scripts where absolute paths are safer.
• Assuming cd succeeds without checking $?.

Performance Notes

cd is instantaneous, but excessive directory changes in scripts can reduce readability.

Security Considerations

Avoid running scripts that rely on implicit working directories; set them explicitly.

Related Commands

pwd, ls, pushd, popd

Practice Exercises

1. Switch to /etc, then back to your previous directory.
2. Script a sequence that enters a directory and verifies it exists before continuing.