getconf - Query system configuration variables

-a - Displays all configuration variables for
the current system and their values.

getconf -a | grep -i name_max

NAME_MAX                           255
_POSIX_NAME_MAX                    255
LOGNAME_MAX                        256
TTY_NAME_MAX                       32
TZNAME_MAX
_POSIX_TZNAME_MAX
CHARCLASS_NAME_MAX                 2048
HOST_NAME_MAX                      64
LOGIN_NAME_MAX                     256