Enhancing cd using a stack

The command cd does not allow for a lot of customization, but there are two built-ins that can be used to extend the functionality of cd.

• pushd pushd <new_dir> will push the current directory onto the directory stack and cd to the new directory. This can be aliased as alias pd=pushd.

• popd popd is the corresponding pop operation. This will pop the top directory on the stack and cd to it. This can be aliased as alias bd=popd.

These are useful when you need to traverse a number of directories but need to return to your current location when done. Of course, if you just need to toggle between two directories, then cd - will do the trick.