I believe the following replacement should fix your problem. Note how I shift out the aircraft ID from @Elements_2 and then join the remainder of the elements together to append to the line in question. You were also missing a few line breaks. Let us know if this fixes it.

if (defined $aircraft_id_1){
  open(INFILE_2,"<${file_2}") or die "Can't open ${file_2} : $!";
  while (my $line_2 = <INFILE_2>){
    chomp($line_2);
    my @Elements_2 = split(/;/, $line_2);
    my $aircraft_id_2 = shift @Elements_2;
    if ($aircraft_id_1 eq $aircraft_id_2){
      print OUTFILE join(';',@Elements_2), "\n";
    }
  }
  close INFILE_2;
} else { print OUTFILE (";" x (40-$meter)), "\n" }

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In reply to Re: concatenation of lines from two different files by dogz007
in thread concatenation of lines from two different files by steph_bow

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