grep
$ grep [--recursive] [--extended-regexp] [--fixed-strings] [--regexp Pattern] [--file File] [-i] [--line-numbers] [--invert-match] [--quiet] [--no-messages] [--binary-mode ] [--text] [-I] [--color WHEN] [--no-hyperlinks] [--count] [file...]-r, --recursive: Recursively scan files-E, --extended-regexp: Extended regular expressions-F, --fixed-strings: Treat pattern as a string, not a regexp-e Pattern, --regexp Pattern: Pattern-f File, --file File: Read patterns from a file-i: Make matches case-insensitive-n, --line-numbers: Output line-numbers-v, --invert-match: Select non-matching lines-q, --quiet: Do not write anything to standard output-s, --no-messages: Suppress error messages for nonexistent or unreadable files--binary-mode: Action to take for binary files ([binary], text, skip)-a, --text: Treat binary files as text (same as --binary-mode text)-I: Ignore binary files (same as --binary-mode skip)--color WHEN: When to use colored output for the matching text ([auto], never, always)--no-hyperlinks: Disable hyperlinks-c, --count: Output line count instead of line contentsfile: File(s) to process