First, I would improve the indentation: 
while ($line = <DATA>)
{
     if ($line =~ /WNT/ || $line =~ /UNX/)
     {
          print "$line\n";
     }
     
     if ($flag)
     {
         if ($target_db ne 'sql')
         {
             next if ($line =~ /$target_db/i);
         }
         else
         {
              next if ($line =~ /informix/i || $line =~ /oracle/i)
         }
         
         print $FH "$line";
         if ($line =~ /$target_os/)
         {
             undef $flag;
             next;
          }
      }
        
      if ($line =~ /UNX/ || $line =~ /WNT/ || $line =~ /COMPONENT/)
      {
          if(!(defined $flag))
          {
              $flag = 1;
              print $FH "$line";
          }
      }
}

[download]
This is probably wrong: 
if ($line =~ /UNX/ || $line =~ /WNT/ || $line =~ /COMPONENT/)
{
    if(!(defined $flag))
    {
        $flag = 1;
        print $FH "$line";
    }
}

[download]
In a code like this, 
if ($line =~ /$target_os/)
         {
             undef $flag;
             next;
          }

[download]
NEVER, repeat NEVER fiddle fiddle around with undef as a "false" value (except in rare cirsumstances). If you mean that $flag should be "false", set $flag to "0 (zero)". A simple rationale is that if you want to print $flag for debugging, "undef" is an error. Another rationale would be that you KNOW that it is "false" not "undefined"!. So say so!

the above code is hard for me to understand your intent. Can you post some set of data and the "pass" and "fail" cases? That would be most helpful.

In reply to Re: Looking for less code by Marshall
in thread Looking for less code by Sun751

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