#!/usr/bin/perl

use warnings;
use strict;

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 ( $line =~ /\s+.* one Link Start$/){
         next unless($line=~/\s+.*second Link Start\s*--%>$/);
         $line =~ s/\s+--%>//;
        s/\s+.* one Link Start$/\s+.* one Link Start\s*--%>/gi;
        
    }
    elsif ($line =~ /\s+.* second Link Start$/){
         next unless($line=~/\s+.*oneLink Start\s*--%>$/);
         $line =~ s/\s+--%>//;
        s/\s+.* second Link Start$/\s+.* second Link Start\s*--%>/gi;
        
   }
    
}

close $fh;
print $line;

 open(my $output_fh, '>', 'hii.txt')
        or die "Unable to open file  for writing: $!";
    print $output_fh $line;
    close $output_fh;