Combine two text files and compare old vs new, replace if changed

compare.sh

#!/bin/bash

FILE="/home/user/replaceable.txt";
TMPFILE="/tmp/file.txt";
FILE1="/home/user/file1";
FILE2="/home/user/file2";

# generate new key in temp location
cat $FILE1 $FILE2 > $TMPFILE;

# compare the files
if /usr/bin/cmp -s "$TMPFILE" "$FILE" ; then
      /bin/echo 'Files are equal, doing nothing.'
else
      /bin/echo 'Files changed.'
      /bin/rm $FILE;
      /bin/cp $TMPFILE $FILE;
fi

/bin/rm $TMPFILE;