4.3. Other useful commands# These are some additional commands that you might find useful. 4.3.1. df — report disk usage 4.3.2. du — estimate disk usage of files or directories 4.3.3. find — search for files 4.3.4. free — view free and used memory 4.3.5. locate — find files using their names 4.3.6. which — locate a command