Chech all files MD5 in one subdirectory, find out the same one.

judge_md5.sh

#!/bin/sh
# Sum student's upload files MD5.
# Check whether they copy file each other.
# Tested in CentOS Linux.

dir=`date +%Y.%m.%d`
output="result.html"
echo -e "<pre>\n$dir" >> $output
md5sum $dir/* | sort | uniq -Dw32 | sed -e "s/$dir\///" >> $output
echo "</pre>" >> $output