The small script is used to parse an nginx (or any other webserver) access log and output the list of the last connected SOGo users, sorted by date of connexion.

#!/usr/bin/perl

use strict;
use warnings;

my $logfile = shift;
$logfile ||= "/var/log/nginx/access.log";

my %seen = ();
open LOG, "<$logfile" or die "Can't open '$logfile': $!\n";
while ()
{
        if (m#\[([^\]]+)\].*POST /SOGo/so/([^/]+)/Mail//#)
        {
                $seen{$2} = $1;
        }
}
close LOG;

sub bydate { $seen{$a} cmp $seen{$b}; }

foreach (sort bydate keys %seen)
{
        printf "%-12s %s\n", $_, $seen{$_};
}

exit(0);