open(FILE, "<x.log");
my @array = <FILE>;
close(FILE);

open(FILE, "<y.log");
my @array1 = <FILE>;
close(FILE);

open(FILE, ">>file.txt");
my @array2 = <FILE>;
foreach $_ (@array & @array1) {
         @array2 = grep {$_ =~ "mti_clk_chk:"} (@array);
                  print FILE "@array2";
          print FILE "n n n";

         @array2 = grep {$_ =~ "mti_clk_chk:"} (@array1);
                  print FILE "@array2";
                  close(FILE);
exit;
}