.SH "NAME"
-finddup \- A simple command line utility for size-sorting files
+finddup \- Find files common to two directories (or not)
.SH "SYNOPSIS"
-\fBfinddup\fP [OPTION]... [FILE]...
+\fBfinddup\fP [OPTION]... DIR1 [[not:]DIR2]
.SH "DESCRIPTION"
-\fBfinddup\fP is a command line utility to find duplicate files, files
-common to two directories or files existing in one directories and not
-in another one.
+With a single directory argument, \fBfinddup\fP prints the duplicate
+files found in it. With two directories, it prints either the files
+common to both DIR1 and DIR2, or with the not: prefix, the ones
+present in DIR1 and not in DIR2.
.SH "OPTIONS"
.TP
.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"