So you want the last non-empty line in your file? I am using a string instead of your file.

use strict;
use warnings;

my $string; # replacement for your file
$string .= "abc($_) = xyz(".($_-1).");\n" for 1..10;

my $line;
for ( split /\n/, $string ) {
        $line = $_ if $_;
}
print $line,"\n";

# alternatively
print +(split /\n/, $string)[-1],"\n";
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