It's not necessarily true that it is "unable to perform the last line of code".

The code after the or will be run if the results of the previous code was 0, empty string, or undefined. So if $names{1} is any of those things, your die will be called.

Is that die in the right place anyway? Looks like it should be after your open:

open (name, "<data/gly.txt") or die "unable to open";
[download]

It's more common to use CAPS for file handles, by the way.

Hope this helps - if not please post a specific example of your input to illustrate what's going on.