-bash-3.2$ ./duplicate_files.pl /users/scripts/perl/test/
file2 is a duplicate file with MD5 of d41d8cd98f00b204e9800998ecf8427e
file1 is a duplicate file with MD5 of 5bb062356cddb5d2c0ef41eb2660cb06
file3 is a duplicate file with MD5 of d41d8cd98f00b204e9800998ecf8427e
file4 is a duplicate file with MD5 of d41d8cd98f00b204e9800998ecf8427e
file5 is a duplicate file with MD5 of 5bb062356cddb5d2c0ef41eb2660cb06
file6 is not a duplicate file, It's md5sum is d617c2deabd27ff86ca9825b2e7578d4