open (INFILE_link,"<$fh") or die $!;
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That would be better as:

open my $INFILE_link, '<', $fh or die "Could not open '$fh' because: $
+!";
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while (my $line = <INFILE_link>) {
    chomp $line;
    my @line_array = split(/\s+/, $line);
    push (@file_array, \@line_array);
}
[download]

That would be better as:

while ( <$INFILE_link> ) {
    push @file_array, [ split ];
}
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Or maybe:

while ( my $line = <$INFILE_link> ) {
    push @file_array, [ split ' ', $line ];
}
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   my ($i, $a, $b, $c, $d, $x, $w, $y, $z, $ta, $tb, $tc, $td);
         
       $a= $b= $c= $d= $x= $w= $y= $z= $ta = $tb =$tc =$td= 0;
[download]

That might be better as:

   my ( $i, $a, $b, $c, $d, $x, $w, $y, $z, $ta, $tb, $tc, $td ) = ( 0
+ ) x 13;
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Or maybe:

   $_ = 0 for my ( $i, $a, $b, $c, $d, $x, $w, $y, $z, $ta, $tb, $tc, 
+$td );
[download]