-c, --count           # print the count of matching lines. suppresses normal output
    --color[=WHEN]    # applies color to the matches. WHEN is never, always, or auto
-m, --max-count=NUM   # stop reading after max count is reached
-o, --only-matching   # only print the matched part of a line
-q, --quiet, --silent
-s, --no-messages     # suppress error messages about nonexistent or unreadable files