The shell (or command-line) is the most commonly used (for advanced operations) interface to Unix-like operating systems. In this session we'll introduce some of the most commonly used command-line/shell features and how they may be used in a hypothetical research project, using real astronomical data sets. The session plan (with a listing of used commands and short explanation) is available here: https://gitlab.com/makhlaghi/smack-talks-iac/-/blob/master/smack-2-shell.md