my $filename = 'words';
open(my $myfile, '+>', $filename)
    or die "Cannot open file '$filename' for writing and reading: $!";
print $myfile @words;

seek($myfile, 0, SEEK_SET);
srand;
rand($.) < 1 and $line = $_ while <$myfile>;
close $myfile
    or die "Cannot close file '$filename': $!";