use warnings;
use strict;
 my $fg=0;
my $i=0;
open(FF ,"lib");
open (FF1,>lib1");

while(<FF>)
{
  my  $lin =$_;
  print FF1 $lin;
   if ($lin=~m/pattern to be patched for stat copying/)
  {   $fg=1;
   }
   if ($fg)
{  

   $lin=$_;

  my  @arr =$lin[$i];
     $i++;
 }
if($lin=~m/pattern where to stop copying & repeating/)
{ $fg=0;
}

}
  if ($fg==0)

{
  for (my $j=0;$j<$i;$j++)

{
   print FF1 @arr[$j];
}
}
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Congratulations, you're getting closer :)

Your if logic is clear now, and correct, you're almost finished

But, your code once again does not compile, and has not been tidied, and you're still not push-ing onto the array

You attempt to compensate by using an index, but you're using it on the wrong variable

strict tells you about this

Global symbol "@lin" requires explicit package name

Global symbol "@arr" requires explicit package name

There is no @lin array, and @arr does not exist outside of the if block, where you assign to it, instead of pushing

You need to increase the scope of @arr, by declaring it outside the while loop, the same as you did $fg

You need to push $lin onto @arr

Unsure of what i'm talking about? You should read the basic datatypes, three, Arrays: A Tutorial/Reference, Lexical scoping like a fox

• Tutorials
• Getting Started with Perl
• Data Types and Variables
• the basic datatypes, three
• Data Type: Array
• Arrays: A Tutorial/Reference
• Getting Deeper Into Perl
• Variables and Scoping
• Variable Scoping in Perl: the basics
• Lexical scoping like a fox
  

i am not using push because my file is very huge around 400 lines so i dont want to run out of mem and also i am not using any module .. so if you can write the certain part where i am making mistake.