# grep > Matches patterns in input text. > Supports simple patterns and regular expressions. - Search for a pattern within a file: `grep {{search_pattern}} {{path/to/file}}` - Search for an exact string: `grep -F {{exact_string}} {{path/to/file}}` - Search for a pattern [R]ecursively in the current directory, showing matching line [n]umbers, [I]gnoring non-text files: `grep -RIn {{search_pattern}} .` - Use extended regular expressions (supporting `?`, `+`, `{}`, `()` and `|`), in case-insensitive mode: `grep -Ei {{search_pattern}} {{path/to/file}}` - Print 3 lines of [C]ontext around, [B]efore, or [A]fter each match: `grep -{{C|B|A}} 3 {{search_pattern}} {{path/to/file}}` - Print file name with the corresponding line number for each match: `grep -Hn {{search_pattern}} {{path/to/file}}` - Use the standard input instead of a file: `cat {{path/to/file}} | grep {{search_pattern}}` - Invert match for excluding specific strings: `grep -v {{search_pattern}}`