I have the following three lines in a text file

i.e text file contains 

bit        rs_1 ;
bit        rs_2 ;
bit        rs_3 ;

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when i=2 then the text file should contain 
bit        rs_1 ;
bit        rs_2 ;

[download]
when i=4 the text file should contain 
bit        rs_1 ;
bit        rs_2 ;
bit        rs_3;
bit        rs_4;

[download]
I have the following code , where is the problem ? 
my $file = 'abc.txt';

{
    open my $in_fh, '<', $file or die "Cannot open input file: $!\n";
    flock $in_fh, LOCK_EX | LOCK_NB or die "Cannot obtain a lock on $f
+ile: $!\n";

    my $temp_out = File::Temp->new(TEMPLATE => "$0-$$-XXXXX");

    while (my $line = <$in_fh>) {
  while ( $line =~ /-abc\s(\d+)/g ) {
   my $first = $1;
   
   if (my ($tail) = $line =~ /^\.march_endSP)(.*)/) {
   print(".rs_$_$tail\n") for 1..$first;
} else {
   print($line);
}
  }
    
    close $in_fh or die "Failed to close $in_fh. Aborting. $!\n";

    $temp_out->flush;
    eval {
        move($temp_out->filename, $in_fh);
    } or do {
        warn "Failed to swap $temp_out into $in_fh: $!\n";

    };
}

[download]
I am unable to get the output, where is the mistake ?

In reply to How the lines will get modified as per value of i by suvendra123

Title:
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