# grep > Matches patterns in input text. > Supports simple patterns and regular expressions. - Search for an exact string: `grep {{search_string}} {{file_path}}` - Search in case-insensitive mode: `grep -i {{search_string}} {{path/to/file}}` - Search recursively (ignoring non-text files) in current directory for an exact string: `grep -rI {{search_string}} .` - Use extended regular expressions (supporting `?`, `+`, `{}`, `()` and `|`): `grep -E {{^regex$}} {{path/to/file}}` - Print 3 lines of context around each match: `grep -C 3 {{search_string}} {{path/to/file}}` - Print the count of matches instead of the matching text: `grep -c {{search_string}} {{path/to/file}}` - Print line number for each match: `grep -n {{search_string}} {{path/to/file}}` - Print file names with matches: `grep -l {{search_string}} {{path/to/file}}` - Use the standard input instead of a file: `cat {{path/to/file}} | grep {{search_string}}` - Invert match for excluding specific strings: `grep -v {{search_string}}`