You should have access to a computer with Bash 4.0 or higher installed or available, and be able to type commands into it via a TTY, terminal emulator, Telnet, or SSH connection (for example, using PuTTY). This book does give some guidance in the first chapter on how to install Bash on your system if it's not already there, or if the installed version is too old (as may be the case on macOS X). You will need either administrative-level (root) access to the computer to install Bash yourself, or a cooperative systems administrator to help you.
If you are not sure which operating system to use, we recommend the Ubuntu distribution of GNU/Linux, available from https://www.ubuntu.com/. The LTS (Long Term Support) ...
