Добавление недостающих строк при сравнении двух файлов

#!/bin/bash
Source_file=/home/user/source.file
Dest_file=/home/user/dest.file
 
IFS-$'\n'
set -f
 
for var in $(cat $Source_file)
do
      if grep -iq $var $Dest_file
then
      echo "$var already is in file!!"
else
      echo "$var REJECT will be added to $Dest_file"
fi
done

#!/usr/bin/env perl -w
use strict;
 
open SRC, "Source.file"      or die $!;
open DST, "Destination.file" or die $!;
 
undef $/;
my @src = <SRC> =~ /\S+/mg;
my %dst = <DST> =~ /(\S+)\s+(REJECT|OK)/mgi;
 
close SRC;
close DST;
 
$dst{"\L$_"} = "REJECT" for @src;
 
open NEW, ">Destination.new" or die $!;
for ( sort keys %dst ) {
 
    printf NEW "%-20s %-s\n", $_, $dst{$_};
}    
 
 
print "Result in the file Destination.new\n";

while read var ; do
 
    if [ "$var" = "xxx.ru" ] ; then
        sed -i "/$var/s/OK/REJECT/" "$Dest_file"
        continue
    fi
 
    if grep -iqF "$var" "$Dest_file" ; then
        echo "$var already is in file!!"
    else
        echo "$var REJECT" >>"$Dest_file"
        echo "$var REJECT will be added to $Dest_file"
    fi
 
done <"$Source_file"

if grep -iFq "xxx.ru" "$Source_file" ; then
    sed -i "/xxx.ru/s/OK/REJECT/" "$Dest_file"
fi
cat <"$Dest_file" <(sed 's/$/ REJECT/' "$Source_file") | sort -uk1,1 >"$Dest_file".new
mv "$Dest_file"{.new,}

cat <(sed 's/$/ REJECT/' "$Source_file") <"$Dest_file" | sort -uk1,1 >"$Dest_file".new
mv -f "$Dest_file"{.new,}

grep -vFf "$Source_file" "$Dest_file" >"$Dest_file".new
sed 's/$/REJECT/'  "$Source_file" >>"$Dest_file".new
mv -f "$Dest_file"{.new,}

grep -F "$(grep OK sour-dest/Destination |cut -d' ' -f1 )" sour-dest/Source |xargs -Iarg sed -i 's/arg.*/arg REJECT/g' sour-dest/Destination

grep -vF "$(cut -d' ' -f1 sour-dest/Destination)" sour-dest/Source |xargs -Iarg echo arg REJECT >> sour-dest/Destination