#!/usr/bin/perl

use warnings;
use strict;
my $pattern1='Prod Link Start';
my $pattern2='Dev Link Start';

open my $fh, '<', 'hii.txt' or die "Can't open the damn file for reading!: $!";

my @file_content;


while ( my $line = <$fh> ){
    chomp $line;


    if ( $line =~/$pattern1/i && !/--%>$/){
      print $line;
     $line.="--%>";
   push @file_content, "$line\n";
   next;
        
   }
    elsif ( $line =~/$pattern1/i && /--%>$/){
        $line = ~ s/--%>//g;
        push @file_content, "$line\n";
  next;
        
   }

if ( $line =~/$pattern2/i && !/--%>$/){
      print $line;
     $line.="--%>";
   push @file_content, "$line\n";
   next;
        
   }
    elsif ( $line =~/$pattern2/i && /--%>$/){
        $line = ~ s/\s--%>//;
        push @file_content, "$line\n";
  next;
        
   }
    

    push @file_content, "$line\n";
}

close $fh;

open $fh, '>', 'hii.txt' or die "Can't open the damned file for writing: $!";
print $fh @file_content;
close $fh;