Чем в GNU/Linux можно файлы-дубликаты искать?

#!/bin/sh
#	2 минуты 12.38 секунд  на 12'989 файлов общим размером 10'026'786'125 байт
#		(стало: 9'919'093'813 байт)
#	1 минута 13.00 секунд на 10'399 файлов общим размером 27'171'656'169 байт
#		(стало: 26'401'660'287 байт)
#	1 минута 17.82 секунд на 8'686 файлов общим размером 11'474'216'791 байт
#		(стало: 11'131'537'062 байт)
#	3 минуты 19.77 секунд на 16'257 файлов общим размером 70'697'892'519 байт
#		(стало: 69'132'667'051 байт)
#
FILELIST="/tmp/filelist_4_mysql"
SQLFILE="/tmp/tmp_4_mysql"
OUTP="/tmp/double_files"
DB="/tmp/filelistdb"

STEP_CNTR=0
#DUP_CNTR=0

if [ "$1" = "-h" ]; then
	echo "Usage: $(basename $0) [-h|-d|-l]"
	echo -e "\t-h\tshow this help"
	echo -e "\t-l\tmake hardlinks for duplicates"
	echo -e "\t-d\tdelete duplicates"
	exit 1
fi

function SQL(){
	echo -e $* | sqlite3 $DB
}

function SQLF(){
	sqlite3 $DB < $SQLFILE
}


function Step(){
	STEP_CNTR=$[$STEP_CNTR + 1 ]
	echo -e "\n\e[1;32m$STEP_CNTR\t\t$*...\e[0m"
}

rm -f $FILELIST $SQLFILE $OUTP $DB

Step "Init database"
SQL "create table files(filename string, filesize integer); create table dups(filename string, filemd5 long);"

Step "Making list of files"
find  -type f -printf "%p\t%s\n" > $FILELIST

Step "Finding files with same size"
cat > $SQLFILE << EOF
delete from files;
.mode tabs
.import /tmp/filelist_4_mysql files
delete from files where filesize in (select filesize from (select filesize,count(*) c from files group by filesize having c = 1) T);
delete from files where filesize = 0;
select filesize from files group by filesize;
EOF

SQLF > $OUTP

cat > $SQLFILE << EOF
delete from dups;
.mode tabs
.import /tmp/filelist_4_mysql dups
delete from dups where filemd5 in (select filemd5 from (select filemd5,count(*) c from dups group by filemd5 having c = 1) T);
select filename from dups group by filemd5;
EOF

Step "Finding duplicates"
while read SIZE
do
	rm -f $FILELIST
	SQL "select filename from files where filesize = $SIZE ;" | while read FILE
	do
		MD=$(sha1sum -b "$FILE" | awk '{print $1}' 2>/dev/null);
		if [ "$MD" != "" ]; then
			echo -e "$FILE\t$MD" >> $FILELIST
		else
			echo -e "\e[1;31;40mCant read MD5 of $FILE\e[0m\nTrace:"
			SQL "select filename from files where filesize = $SIZE;" 
		fi
	done
	SQLF | while read FILE
	do
		echo -e "\n\e[1;41;33m$FILE\e[36m has dublicates:\e[0m"
		SQL "select filename from dups where filemd5 = (select filemd5 from dups where filename = \"$FILE\") AND filename != \"$FILE\";"  | while read D_FILE
		do
			echo -e "\e[1;32;40m$D_FILE\e[0m"
			[ "$1" = "-d" ] && rm -f "$D_FILE" && echo "deleted"
			[ "$1" = "-l" ] && ln -f "$FILE" "$D_FILE" && echo "linked"   #|| ln -fs "$FILE" "$D_FILE" || echo -e "\e[1;31;40merror linking $FILE to $D_FILE!!!\e[0m"
		done
	done
done < $OUTP

Step "Deleting trash"
#echo "delete from files; delete from dups;" 
rm -f $FILELIST $SQLFILE $OUTP $DB