multiple
Oliver Bandel <obandel at first.in-berlin.de> - March 03rd 2000, 07:11 EST 

multiple prints the filenames of files which contains the same data. 
The names of the files which should be compared will be piped in 
(eg., use find). Normally (without switches) only superfluous filenames 
will be printed. multiple can optionally print names of ALL equal files, 
compare after the first empty line (eg, to ignore mailheaders), pay 
attention to files with size == 0, and delete superflous files 
(and print names of non-dfeleted).