.SH "SYNOPSIS"
-\fBfinddup\fP [OPTION]... [FILE]...
+\fBfinddup\fP [OPTION]... DIR1 [[^]DIR2]
.SH "DESCRIPTION"
common to two directories or files existing in one directories and not
in another one.
+With a single directory argument, prints the duplicate files found in
+it. With two directories, prints the files common to both.
+
+If the second directory name starts with a ^, prints the files
+existing in DIR1 which do not exist in DIR2.
+
.SH "OPTIONS"
.TP
\fB-h\fR
.SH "BUGS"
-None known, probably many though.
+Every pair of different files with same content are listed, which
+results in K^2 printed lines when K files are similar.
.SH "AUTHOR"