If that is really what you want to do then you can change the 'while' loop to a simple 'if', because that's what it effectively is. The while loop will never be executed more than once, because if $content is anything but $x the while loop will exit immediately

         if ($content == $x){
             print ($content, $content1, $content2,
                    $content3, $content4);
             $x++;
          }
[download]

You don't need the close as the files are automatically closed on program exit or reopening

Yes, I understand what you mean. Now is there a way I can read all the files in one code, instead of opening one by one? Thanks for the assistance

Yes there is:

my @content;
foreach ('','.1','.2','.3','.4') {
  open(my $fh,'<',$string.$_) or die "Could not open $string.$_ : $!\n
+";
  push @content, scalar <$fh>;
}
if ($content[0] == $x){
  print @content;
  $x++;
}
[download]

UPDATE: removed bug. UPDATE2: removed another bug found by anon monk