print lines matching a pattern

-q, --quiet, --silent
       Quiet; do not write anything to standard output.  Exit immediately with zero status if  any  match
       is  found,  even  if  an  error  was  detected.   Also see the -s or --no-messages option.  (-q is
       specified by POSIX.)

-w, --word-regexp
       Select  only  those lines containing matches that form whole words.  The test is that the matching
       substring must either be at the beginning of the line,  or  preceded  by  a  non-word  constituent
       character.   Similarly,  it  must  be  either  at  the  end  of the line or followed by a non-word
       constituent character.  Word-constituent characters are letters, digits, and the underscore.

grep searches the named input FILEs (or standard input if no files are named, or if a single hyphen-minus
(-) is given as file name) for lines containing a match to the given PATTERN.  By  default,  grep  prints
the matching lines.