% grep BOB tmpfile        {search 'tmpfile' for 'BOB' anywhere in a line}

% grep -i -w blkptr *     {search files in CWD for word blkptr, any case}

% grep run[- ]time *.txt  {find 'run time' or 'run-time' in all txt files}

% who | grep root         {pipe who to grep, look for root}