Thanks everyone for the responses, and especially thanks for the examples using the various parsing modules. I now have those to refer to in the future.

I've settled on a simplified version of my original code, incorporating the suggestions from [id://grandfather], as follows:

#!/usr/bin/perl -w
use strict;

my $datafile = "stuff.csv";
my @fields;
my $data;

open DATA, "<$datafile" or die "Could not open $datafile:$!\n";
# Grab the first (header) line, discarding the first two fields
$_ = <DATA> or die "Empty file";
chomp((undef, undef, @fields) = (split /\t/));

# Grab the rest, and populate the hashref
while (<DATA>) {
    chomp();
    my ($user, @userdata) = (split /\t/);
    $data->{$user}{$_} = shift @userdata for (@fields);
}
close DATA;
[download]

This is much "nicer" than my original, and I'm now a happy vegemite :)

--Darren