filterif [argument1] [argument2] [argument3] ...
filterif is free software for GNU/Linux and other UNIX(tm)-like operating systems. filterif is distributed under the GNU General Public License and is written in C.
filterif filters lines of text from standard input to standard output. Each argument passed to filterif is matched against the input received. When a match is found, the current inupt is discarded. When a match is not found, the input passes to standard output. In simpler terms, think of it as the reverse of grep.
du | filterif /bin/laden
cat propaganda | filterif Microsoft ?lippy > propaganda
cat propaganda | grep innovative | filterif Microsoft .NET ?isual ?asic