The line of code I quoted overwrites the contents of @data each time through the loop. You can open as many files as you like, but the code only ever stores the lines from the last file you read.

A quick fix might be to replace that with push @data, <FH>;.

As a side note, you can loop over the contents of an array without an index with:

for my $name (@data_names)
{
    # open files here
}
[download]