Hi Arun,

I kept the flag when the condition is met, but still processes all lines instead of processing only the matched line.

open (FH, "$ARGV[0]") or die "couldn't open .RES $! file";
@res=<FH>;
close(FH);
$flag=0;
$ARGV[1]="$ARGV[1]_$ARGV[0].txt";

#open (RH, ">$ARGV[1]");
$count=0;
$flag=0;

foreach $line (@res)
{
  if ($line =~ m/\-\-gnu\s/)
  {
    $flag=1;
    chomp($line);
    @new = split(" ",$line);
    foreach $n (@new) 
    {
    if ($n !~ m/^$/)
         {
        #if ($n =~ m/^$/) { next; }
         if ($flag == 1)
         {
        if (($n =~ /^\-D(\w\_\=\d)*/) || ($n =~ /^\-U(\w\_\=\d)*/) && 
+($n !~/^\-I(\w\_\=\d)*/))
             {
            $count++;
            chomp($n);
            print "\n$count $n";
            #print RH "$count $n \n";
         }
         }
     }        
     }    
  }
  $flag=0;  
 #exit; 
}

close (RH);
[download]

Please suggest what mistake i have encountered? Thanks for your suggestions.... BR, Raghvens