$ perl -Mstrict -Mwarnings -Mautodie -e '
    open my $fh, "<", "./pm_1050631_in.txt";
    my $data = do { local $/; <$fh> };
    close $fh;

    my %server;
    my $re = qr{\[(\w+)\]\s+([^[]*)};

    while ($data =~ /$re/g) {
        $server{$1} = join "," => split /\s+/ => $2;
    }

    for (sort keys %server) {
        print "$_:$server{$_}\n";
    }
'
server1:/tmp/location1/file.log,/tmp/location2/file.log
server2:/usr/loc1/file.log,/usr/loc2/file.log
server3:/citrix/dir3/file.log