All scripts for this chapter can be found on GitHub: https://github.com/PacktPublishing/Learn-Linux-Shell-Scripting-Fundamentals-of-Bash-4.4/tree/master/Chapter11. All other tools are still valid, both on your host machine as well as on your Ubuntu virtual machine. For the break-x.sh, for-globbing.sh, square-number.sh, while-interactive.sh scripts only the final version is found online. Be sure to verify the script version in the header before executing it on your system.