.TH filter "" "" Definition
.PC
.PP
A
.I filter
is a program that reads a stream of input, transforms it in a precisely
defined manner, and writes it to another stream.
Two or more filters can be coupled with
.I pipes
to perform a complex transformation on a stream of input.
.SH "See Also"
.Xr "pipe," pipe.d
.Xr "Using COHERENT" using_coh
