#!/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.="--%>";
 my $var = substr($line, -4);
print $var;

if($var !~/--%>/)
{
$line.= "--%>";
print $line;
}
elsif($var = ~/--%>/)
{
 $line = substr($line, 0, - 4);
print $line;
}

push @file_content, "$line\n";
   next;
        
   }
if ( $line =~/$pattern2/i){
    # print $line;
     #$line.="--%>";
 my $var = substr($line, -4);
print $var;

if($var !~/--%>/)
{
$line.= "--%>";
print $line;
}
elsif($var = ~/--%>/)
{
 $line = substr($line, 0, - 4);
print $line;
}

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;