Your code seems to "work" for me. I enter 1,2,3, and I get 3,2,1:

use warnings;

print "Enter some lines, then press Ctrl-D:\n"; # or maybe Ctrl-Z
@lines = <STDIN>;
@reverse_lines = reverse (@lines);
print @reverse_lines;

__END__

Enter some lines, then press Ctrl-D:
1
2
3
3
2
1
[download]

If you enter a palindrome, like 1,2,1, then the reverse will look the same as what you entered.