my %user_login;
while (my $line = <errlog>) {
  chomp $line;
  next unless ($line =~ /Login succeeded/);
  my ($date,$time,$username)=(split(' ',$line))[0,1,6];
  $user_login{$username}="$date $time";
}

for my $record(sort keys %user_login) {
  print "$record logged in at $user_login{$record}\n";
}