in reply to Perl memset equivalent?

It's hard to guess what you are trying to achieve exactly... Do you want:

@stn_names = (0) x STN_NAME_LEN;
which gives you an array filled with five zeros? Or do you want something more like:
my $s = pack "c5", (0)x5;
which will give you a string packed with 5 nulls?

"My two cents aren't worth a dime.";