#!/bin/bash
cp /home/lucas/files.txt /home/lucas/files1.txt
input="/tmp/rsync_files.txt"
while IFS= read -r var
do
  echo "$var"
  #var=$(echo $var 
  cat /home/lucas/files1.txt | grep -vF "$var" > /home/lucas/files2.txt
  mv /home/lucas/files2.txt /home/lucas/files1.txt
#sleep 10
done < "$input"

while IFS= read -r var; do ls "$var" >/dev/null; done < /home/lucas/files1.txt