'Returns the command line for reading a crontab'

def _read_user_execute(self):

    user = ''
    if self.user:
        if (platform.system() == 'SunOS'):
            return ("su    %s    -c    '%s    -l'" % (pipes.quote(self.user), pipes.quote(CRONCMD)))
        elif (platform.system() == 'AIX'):
            return ('%s    -l    %s' % (pipes.quote(CRONCMD), pipes.quote(self.user)))
        elif (platform.system() == 'HP-UX'):
            return ('%s    %s    %s' % (CRONCMD, '-l', pipes.quote(self.user)))
        else:
            user = ('-u    %s' % pipes.quote(self.user))
    return ('%s    %s    %s' % (CRONCMD, user, '-l'))
