Advanced `grep` and `find` Patterns

Welcome back! In previous lessons, you've learned the basics of grep for filtering text and find for locating files.

Today, we'll dive into advanced patterns. This means using more powerful regular expressions with grep and sophisticated criteria with find to achieve highly precise searches.

The standard grep command uses Basic Regular Expressions (BRE). For more power, we often switch to Extended Regular Expressions (ERE).

• Use the -E option (or egrep) to enable ERE.
• ERE allows features like + (one or more), ? (zero or one), | (OR), and () for grouping without needing to escape them.