#!/usr/bin/perl
use strict;
use warnings;

my $noe1=0;
my @array;
my $i;
#gesamtzahl der events
my $noe;

while(<>) { 
my @stuff=split(' ');

 if(/UQMD/){
 }
 elsif(/projectile:/){
 my $protar=$_
 }
 elsif(/equation_of_state:/){
  my $ecm=$stuff[5];
  my $midy=log($ecm/0.938);
  my $elab=$stuff[3];
  my $plab=$stuff[7];
 }
 elsif(/event#/){
  $noe++                    # numbers of events: noe
 }      
 else{
  if($#stuff==14){ 

   my @x=@stuff[0..3];   
   my @p=@stuff[4..7];
   my @id=@stuff[8..11];

   my $mass=$id[0];
   my $ityp=$id[1];
   my $iz2=$id[2];
   my $charge=$id[3];


    if ($ityp==27) {
      $array[$noe]++;    
     }
     }
     }
     }
    for($i=0..$#array){
      if($array[$i]==2){
      print($i, "\t", $array[$i]);
      }
    }

-bash$ perl datei.pl datafile.f14
Argument "" isn't numeric in array element at datei.pl line 48, <> line 2175503
Use of Uninitialized value in numeric eq (==) at datei.pl line 48, <> line 2175503.