There is a bug, @words ends up only containing the "words" in the last line ;-) as you are resetting it for each line.

Also there was no need for two splits, just one is good enough, and better use strict ;-)

use Data::Dumper;

use strict;
use warnings;

open FILE, "a.txt";
undef $/;
$_ = <FILE>;
close(FILE);
my @words = split;

print Dumper(\@words);
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