use strict;
use warnings;
my @data;
while(<DATA>){
        push @data, { 'user' => $1 }  if /^user: (\w+)/;
        $data[-1]{'summary'}     = $1 if /summary\s+"(.+)"/;
        $data[-1]{'accesslevel'} = $1 if /access-level\s+(\S+)/;
        $data[-1]{'group'}       = $1 if /group\s+(\S+)/;
}
for my $user (@data){
        print join ',', map { $user->{$_} // '' } qw(user summary accesslevel group);
        print "\n";
}
__DATA__
user: myus44 [up]
------------
 admin-state enabled
 summary "Johnny Cash"
 access-level group-defined
 group mi-group  [up]

user: jar1543 [up]
------------
 admin-state enabled
 summary "Lara Croft"
 access-level group-defined
 group jar-head  [up]

user: myprivilegeduser [up]
-----------
admin-state enabled
access-level privileged