grep

Website: http://www.gnu.org/software/grep/

grep is a command-line utility for searching plain-text data sets for lines matching a regular expression. It is one of the most fundamental and widely used tools in Unix and Linux systems, available on virtually every POSIX system.

Key Features

• Regular Expression Search — Basic, extended, and Perl-compatible regex support
• Recursive Search — Search entire directory trees with -r
• Color Output — Highlight matches with --color
• Context Lines — Show lines before, after, or around matches (-B, -A, -C)
• Invert Match — Show lines that do not match a pattern
• Binary File Handling — Skip or search binary files intelligently

Platform

Linux, macOS, BSD, Windows (via WSL/Cygwin)

Licence

GNU General Public License v3

Website

http://www.gnu.org/software/grep/