#!/usr/bin/perl
use strict;
use warnings;
my $alter = "3";
#assign a value to alter different than 0 or 1 which is used later ...
my $openfile = "$ENV{SystemRoot}/win.ini";
{
open (MYFILE, ">>$openfile")or die "Can't open file 1: $!\n"; #open for write, append not read!
open (TEST, "c:/windows/win.ini") or die "Cant open file $!\n";

while(<TEST>) {
    if ( $_ =~ /[ARTEC]/ )  {
        my $alter = 1;
    } else {
    my $alter = 0;
    }
  } 
}  
  if ($alter == 1) {
      #do something; 
      print "..";   
     }
 
close(MYFILE);
close(TEST);

##</code><code>##

blabla
[ARTEC]
IniFile=f:\vaa\basis\vaa01.ini
bla 

##</code><code>##

use vars qw($change $alter);
$alter = 0;

sub readfile { while(<TEST>) {
    if ( $_ =~ /^\[ARTEC\]$/ )  {
               $alter = 1;
    exit print "found it exiting no need to change something";
          
        }else {
        $change = 1;
        print "n ";
        }        
    }
  return;
  } 
}
if ($alter == 0 and $change == 1) {
       #do something ...
	   print "changed\n";   
      
    }