my %hash;
while (my $line=<IN>) { # I assume an open IN filehandle
  chomp $line;
  ($username, $realname, $pwd) = split /\t/, $line; # I assume tab delimiter
  $hash{$username} = [$realname, $pwd];
}
##</code><code>##

$realname = $hash{'someuser'}->[0];
$pwd = $hash{'someuser'}->[1];