How to Find and Delete Duplicate Files using Script

This shell script will look for duplicate file names within sub directories and prompt to delete. If md5sum of the files same then we conclude its duplicated. This helps system administrator to delete unnecessary copy to reduce used space. The script will ask the user to enter the directory where to search for duplicate files.

Shell Script - Delete duplicate files

#!/bin/bash

#file, where we will store full list of files.
ListOfFiles=/tmp/listoffiles.txt

#we ask user to enter directory where search for duplicated files
echo -n "Please enter directory where to search for duplicated files: "

#we read user input
while read dir

do

#we check if user input is not empty
test -z "$dir" && {

#if user input empty we ask once more to enter directory
echo -n "Please enter directory: "

continue

}

#if directory entered, exit from while loop
break

done

#getting list of files inside entered directory
find $dir -type f -print > $ListOfFiles

#writing list of files to variable
FileList=`cat $ListOfFiles`

#we get number of files
count=`wc -l $ListOfFiles| awk '{print $1}'`

#counter
i=1

#we get files one by one
for file in $FileList

do

#just make this variable empty for every loop
samefiles=""

#we need to get all non-proceeded files
let tailvalue=$count-$i

#we get only filename, without path
filename=$(basename $file)

#getting list of un-proceeded files, and we check if there is file with same filename
samefiles=`tail -${tailvalue} $ListOfFiles | grep $filename`

#starting loop for all same files
for samefile in $samefiles

do

#we get md5sum of filename with same name
msf=`md5sum $samefile | awk '{print $1}'`

#we get md5sum of original file
ms=`md5sum $file | awk '{print $1}'`

#we compare md5sums
if [ "$msf" = "$ms" ]; then

#if md5sums equal, we tell user about duplicated files
echo "File $file duplicated to $samefile"

#end of if loop
fi

#end of while loop
done

#increase counter by 1
let i=$i+1

done