如何使用 Python 在 Windows 上检索附近无线 LAN 网络的信号强度?
我想显示或绘制值。
如果您在Windows上,您可能想要使用 WLAN API,它提供了“WlanGetAvailableNetworkList()”函数(有关用法,请参阅API 文档)。我不知道有任何 python 包装器,因此您可能必须使用ctypesWLANAPI.DLL
自己包装它。我有一个可以执行此操作的初步脚本(为我工作),但它可能很笨拙。您需要阅读文档以了解所有字段的含义:
from ctypes import *
from ctypes.wintypes import *
from sys import exit
def customresize(array, new_size):
return (array._type_*new_size).from_address(addressof(array))
wlanapi = windll.LoadLibrary('wlanapi.dll')
ERROR_SUCCESS = 0
class GUID(Structure):
_fields_ = [
('Data1', c_ulong),
('Data2', c_ushort),
('Data3', c_ushort),
('Data4', c_ubyte*8),
]
WLAN_INTERFACE_STATE = c_uint
(wlan_interface_state_not_ready,
wlan_interface_state_connected,
wlan_interface_state_ad_hoc_network_formed,
wlan_interface_state_disconnecting,
wlan_interface_state_disconnected,
wlan_interface_state_associating,
wlan_interface_state_discovering,
wlan_interface_state_authenticating) = map(WLAN_INTERFACE_STATE, range(0, 8))
class WLAN_INTERFACE_INFO(Structure):
_fields_ = [
("InterfaceGuid", GUID),
("strInterfaceDescription", c_wchar * 256),
("isState", WLAN_INTERFACE_STATE)
]
class WLAN_INTERFACE_INFO_LIST(Structure):
_fields_ = [
("NumberOfItems", DWORD),
("Index", DWORD),
("InterfaceInfo", WLAN_INTERFACE_INFO * 1)
]
WLAN_MAX_PHY_TYPE_NUMBER = 0x8
DOT11_SSID_MAX_LENGTH = 32
WLAN_REASON_CODE = DWORD
DOT11_BSS_TYPE = c_uint
(dot11_BSS_type_infrastructure,
dot11_BSS_type_independent,
dot11_BSS_type_any) = map(DOT11_BSS_TYPE, range(1, 4))
DOT11_PHY_TYPE = c_uint
dot11_phy_type_unknown = 0
dot11_phy_type_any = 0
dot11_phy_type_fhss = 1
dot11_phy_type_dsss = 2
dot11_phy_type_irbaseband = 3
dot11_phy_type_ofdm = 4
dot11_phy_type_hrdsss = 5
dot11_phy_type_erp = 6
dot11_phy_type_ht = 7
dot11_phy_type_IHV_start = 0x80000000
dot11_phy_type_IHV_end = 0xffffffff
DOT11_AUTH_ALGORITHM = c_uint
DOT11_AUTH_ALGO_80211_OPEN = 1
DOT11_AUTH_ALGO_80211_SHARED_KEY = 2
DOT11_AUTH_ALGO_WPA = 3
DOT11_AUTH_ALGO_WPA_PSK = 4
DOT11_AUTH_ALGO_WPA_NONE = 5
DOT11_AUTH_ALGO_RSNA = 6
DOT11_AUTH_ALGO_RSNA_PSK = 7
DOT11_AUTH_ALGO_IHV_START = 0x80000000
DOT11_AUTH_ALGO_IHV_END = 0xffffffff
DOT11_CIPHER_ALGORITHM = c_uint
DOT11_CIPHER_ALGO_NONE = 0x00
DOT11_CIPHER_ALGO_WEP40 = 0x01
DOT11_CIPHER_ALGO_TKIP = 0x02
DOT11_CIPHER_ALGO_CCMP = 0x04
DOT11_CIPHER_ALGO_WEP104 = 0x05
DOT11_CIPHER_ALGO_WPA_USE_GROUP = 0x100
DOT11_CIPHER_ALGO_RSN_USE_GROUP = 0x100
DOT11_CIPHER_ALGO_WEP = 0x101
DOT11_CIPHER_ALGO_IHV_START = 0x80000000
DOT11_CIPHER_ALGO_IHV_END = 0xffffffff
WLAN_AVAILABLE_NETWORK_CONNECTED = 1
WLAN_AVAILABLE_NETWORK_HAS_PROFILE = 2
WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_ADHOC_PROFILES = 0x00000001
WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_MANUAL_HIDDEN_PROFILES = 0x00000002
class DOT11_SSID(Structure):
_fields_ = [
("SSIDLength", c_ulong),
("SSID", c_char * DOT11_SSID_MAX_LENGTH)
]
class WLAN_AVAILABLE_NETWORK(Structure):
_fields_ = [
("ProfileName", c_wchar * 256),
("dot11Ssid", DOT11_SSID),
("dot11BssType", DOT11_BSS_TYPE),
("NumberOfBssids", c_ulong),
("NetworkConnectable", c_bool),
("wlanNotConnectableReason", WLAN_REASON_CODE),
("NumberOfPhyTypes", c_ulong),
("dot11PhyTypes", DOT11_PHY_TYPE * WLAN_MAX_PHY_TYPE_NUMBER),
("MorePhyTypes", c_bool),
("wlanSignalQuality", c_ulong),
("SecurityEnabled", c_bool),
("dot11DefaultAuthAlgorithm", DOT11_AUTH_ALGORITHM),
("dot11DefaultCipherAlgorithm", DOT11_CIPHER_ALGORITHM),
("Flags", DWORD),
("Reserved", DWORD)
]
class WLAN_AVAILABLE_NETWORK_LIST(Structure):
_fields_ = [
("NumberOfItems", DWORD),
("Index", DWORD),
("Network", WLAN_AVAILABLE_NETWORK * 1)
]
WlanOpenHandle = wlanapi.WlanOpenHandle
WlanOpenHandle.argtypes = (DWORD, c_void_p, POINTER(DWORD), POINTER(HANDLE))
WlanOpenHandle.restype = DWORD
WlanEnumInterfaces = wlanapi.WlanEnumInterfaces
WlanEnumInterfaces.argtypes = (HANDLE, c_void_p,
POINTER(POINTER(WLAN_INTERFACE_INFO_LIST)))
WlanEnumInterfaces.restype = DWORD
WlanGetAvailableNetworkList = wlanapi.WlanGetAvailableNetworkList
WlanGetAvailableNetworkList.argtypes = (HANDLE, POINTER(GUID), DWORD, c_void_p,
POINTER(POINTER(WLAN_AVAILABLE_NETWORK_LIST)))
WlanGetAvailableNetworkList.restype = DWORD
WlanFreeMemory = wlanapi.WlanFreeMemory
WlanFreeMemory.argtypes = [c_void_p]
if __name__ == '__main__':
NegotiatedVersion = DWORD()
ClientHandle = HANDLE()
ret = WlanOpenHandle(1, None, byref(NegotiatedVersion), byref(ClientHandle))
if ret != ERROR_SUCCESS:
exit(FormatError(ret))
# find all wireless network interfaces
pInterfaceList = pointer(WLAN_INTERFACE_INFO_LIST())
ret = WlanEnumInterfaces(ClientHandle, None, byref(pInterfaceList))
if ret != ERROR_SUCCESS:
exit(FormatError(ret))
try:
ifaces = customresize(pInterfaceList.contents.InterfaceInfo,
pInterfaceList.contents.NumberOfItems)
# find each available network for each interface
for iface in ifaces:
print("Interface: {}".format(iface.strInterfaceDescription))
pAvailableNetworkList = pointer(WLAN_AVAILABLE_NETWORK_LIST())
ret = WlanGetAvailableNetworkList(ClientHandle,
byref(iface.InterfaceGuid),
0,
None,
byref(pAvailableNetworkList))
if ret != ERROR_SUCCESS:
exit(FormatError(ret))
try:
avail_net_list = pAvailableNetworkList.contents
networks = customresize(avail_net_list.Network,
avail_net_list.NumberOfItems)
for network in networks:
print("SSID: {}, quality: {:2d}%".format(
network.dot11Ssid.SSID[:network.dot11Ssid.SSIDLength].decode(),
network.wlanSignalQuality))
finally:
WlanFreeMemory(pAvailableNetworkList)
finally:
WlanFreeMemory(pInterfaceList)
在linux上,您有几个选择:
标准选项是解析iwlist -scan
. 但是,如果您当前连接到一个 wlan 并且没有以 root 身份运行,它只会返回当前连接的 wlan。
如果您需要更多,最好的方法是查询无线管理器守护程序。在现代 Linux 上,这通常是NetworkManager,尽管wicd变得越来越流行。可以使用 查询这两个管理器dbus
。除非您可以控制客户端在其系统上的内容,否则您可能需要同时支持这两个选项,或者至少支持一个选项并为iwlist
.
所以..我自己基于@fmarks 代码(这对我来说是一个安全的生活),你应该添加WlanScan 函数,否则 RSSI 值将不会刷新。
这是我的扩展代码!
@fmarks 的所有道具!
__author__ = 'Pedro Gomes'
import time
from ctypes import *
from ctypes.wintypes import *
from sys import exit
def customresize(array, new_size):
return (array._type_*new_size).from_address(addressof(array))
wlanapi = windll.LoadLibrary('wlanapi.dll')
ERROR_SUCCESS = 0
class GUID(Structure):
_fields_ = [
('Data1', c_ulong),
('Data2', c_ushort),
('Data3', c_ushort),
('Data4', c_ubyte*8),
]
WLAN_INTERFACE_STATE = c_uint
(wlan_interface_state_not_ready,
wlan_interface_state_connected,
wlan_interface_state_ad_hoc_network_formed,
wlan_interface_state_disconnecting,
wlan_interface_state_disconnected,
wlan_interface_state_associating,
wlan_interface_state_discovering,
wlan_interface_state_authenticating) = map(WLAN_INTERFACE_STATE, xrange(0, 8))
class WLAN_INTERFACE_INFO(Structure):
_fields_ = [
("InterfaceGuid", GUID),
("strInterfaceDescription", c_wchar * 256),
("isState", WLAN_INTERFACE_STATE)
]
class WLAN_INTERFACE_INFO_LIST(Structure):
_fields_ = [
("NumberOfItems", DWORD),
("Index", DWORD),
("InterfaceInfo", WLAN_INTERFACE_INFO * 1)
]
WLAN_MAX_PHY_TYPE_NUMBER = 0x8
DOT11_SSID_MAX_LENGTH = 32
WLAN_REASON_CODE = DWORD
DOT11_BSS_TYPE = c_uint
(dot11_BSS_type_infrastructure,
dot11_BSS_type_independent,
dot11_BSS_type_any) = map(DOT11_BSS_TYPE, xrange(1, 4))
DOT11_PHY_TYPE = c_uint
dot11_phy_type_unknown = 0
dot11_phy_type_any = 0
dot11_phy_type_fhss = 1
dot11_phy_type_dsss = 2
dot11_phy_type_irbaseband = 3
dot11_phy_type_ofdm = 4
dot11_phy_type_hrdsss = 5
dot11_phy_type_erp = 6
dot11_phy_type_ht = 7
dot11_phy_type_IHV_start = 0x80000000
dot11_phy_type_IHV_end = 0xffffffff
DOT11_AUTH_ALGORITHM = c_uint
DOT11_AUTH_ALGO_80211_OPEN = 1
DOT11_AUTH_ALGO_80211_SHARED_KEY = 2
DOT11_AUTH_ALGO_WPA = 3
DOT11_AUTH_ALGO_WPA_PSK = 4
DOT11_AUTH_ALGO_WPA_NONE = 5
DOT11_AUTH_ALGO_RSNA = 6
DOT11_AUTH_ALGO_RSNA_PSK = 7
DOT11_AUTH_ALGO_IHV_START = 0x80000000
DOT11_AUTH_ALGO_IHV_END = 0xffffffff
DOT11_CIPHER_ALGORITHM = c_uint
DOT11_CIPHER_ALGO_NONE = 0x00
DOT11_CIPHER_ALGO_WEP40 = 0x01
DOT11_CIPHER_ALGO_TKIP = 0x02
DOT11_CIPHER_ALGO_CCMP = 0x04
DOT11_CIPHER_ALGO_WEP104 = 0x05
DOT11_CIPHER_ALGO_WPA_USE_GROUP = 0x100
DOT11_CIPHER_ALGO_RSN_USE_GROUP = 0x100
DOT11_CIPHER_ALGO_WEP = 0x101
DOT11_CIPHER_ALGO_IHV_START = 0x80000000
DOT11_CIPHER_ALGO_IHV_END = 0xffffffff
WLAN_AVAILABLE_NETWORK_CONNECTED = 1
WLAN_AVAILABLE_NETWORK_HAS_PROFILE = 2
WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_ADHOC_PROFILES = 0x00000001
WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_MANUAL_HIDDEN_PROFILES = 0x00000002
class DOT11_SSID(Structure):
_fields_ = [
("SSIDLength", c_ulong),
("SSID", c_char * DOT11_SSID_MAX_LENGTH)
]
class WLAN_AVAILABLE_NETWORK(Structure):
_fields_ = [
("ProfileName", c_wchar * 256),
("dot11Ssid", DOT11_SSID),
("dot11BssType", DOT11_BSS_TYPE),
("NumberOfBssids", c_ulong),
("NetworkConnectable", c_bool),
("wlanNotConnectableReason", WLAN_REASON_CODE),
("NumberOfPhyTypes", c_ulong),
("dot11PhyTypes", DOT11_PHY_TYPE * WLAN_MAX_PHY_TYPE_NUMBER),
("MorePhyTypes", c_bool),
("wlanSignalQuality", c_ulong),
("SecurityEnabled", c_bool),
("dot11DefaultAuthAlgorithm", DOT11_AUTH_ALGORITHM),
("dot11DefaultCipherAlgorithm", DOT11_CIPHER_ALGORITHM),
("Flags", DWORD),
("Reserved", DWORD)
]
class WLAN_AVAILABLE_NETWORK_LIST(Structure):
_fields_ = [
("NumberOfItems", DWORD),
("Index", DWORD),
("Network", WLAN_AVAILABLE_NETWORK * 1)
]
DOT11_MAC_ADDRESS = c_ubyte * 6
DOT11_CIPHER_ALGORITHM = c_uint
DOT11_CIPHER_ALGO_NONE = 0x00
DOT11_CIPHER_ALGO_WEP40 = 0x01
DOT11_CIPHER_ALGO_TKIP = 0x02
DOT11_PHY_TYPE = c_uint
DOT11_PHY_TYPE_UNKNOWN = 0
DOT11_PHY_TYPE_ANY = 0
DOT11_PHY_TYPE_FHSS = 1
DOT11_PHY_TYPE_DSSS = 2
DOT11_PHY_TYPE_IRBASEBAND = 3
DOT11_PHY_TYPE_OFDM = 4
DOT11_PHY_TYPE_HRDSSS = 5
DOT11_PHY_TYPE_ERP = 6
DOT11_PHY_TYPE_HT = 7
DOT11_PHY_TYPE_IHV_START = 0X80000000
DOT11_PHY_TYPE_IHV_END = 0XFFFFFFFF
class WLAN_RATE_SET(Structure):
_fields_ = [
("uRateSetLength", c_ulong),
("usRateSet", c_ushort * 126)
]
class WLAN_BSS_ENTRY(Structure):
_fields_ = [
("dot11Ssid",DOT11_SSID),
("uPhyId",c_ulong),
("dot11Bssid", DOT11_MAC_ADDRESS),
("dot11BssType", DOT11_BSS_TYPE),
("dot11BssPhyType", DOT11_PHY_TYPE),
("lRssi", c_long),
("uLinkQuality", c_ulong),
("bInRegDomain", c_bool),
("usBeaconPeriod",c_ushort),
("ullTimestamp", c_ulonglong),
("ullHostTimestamp",c_ulonglong),
("usCapabilityInformation",c_ushort),
("ulChCenterFrequency", c_ulong),
("wlanRateSet",WLAN_RATE_SET),
("ulIeOffset", c_ulong),
("ulIeSize", c_ulong)]
class WLAN_BSS_LIST(Structure):
_fields_ = [
("TotalSize", DWORD),
("NumberOfItems", DWORD),
("NetworkBSS", WLAN_BSS_ENTRY * 1)
]
class WLAN_AVAILABLE_NETWORK_LIST_BSS(Structure):
_fields_ = [
("TotalSize", DWORD),
("NumberOfItems", DWORD),
("Network", WLAN_BSS_ENTRY * 1)
]
WlanOpenHandle = wlanapi.WlanOpenHandle
WlanOpenHandle.argtypes = (DWORD, c_void_p, POINTER(DWORD), POINTER(HANDLE))
WlanOpenHandle.restype = DWORD
WlanCloseHandle = wlanapi.WlanCloseHandle
WlanCloseHandle.argtypes = (HANDLE, c_void_p)
WlanCloseHandle.restype = DWORD
WlanEnumInterfaces = wlanapi.WlanEnumInterfaces
WlanEnumInterfaces.argtypes = (HANDLE, c_void_p,
POINTER(POINTER(WLAN_INTERFACE_INFO_LIST)))
WlanEnumInterfaces.restype = DWORD
WlanGetAvailableNetworkList = wlanapi.WlanGetAvailableNetworkList
WlanGetAvailableNetworkList.argtypes = (HANDLE, POINTER(GUID), DWORD, c_void_p,
POINTER(POINTER(WLAN_AVAILABLE_NETWORK_LIST)))
WlanGetAvailableNetworkList.restype = DWORD
WlanGetNetworkBssList = wlanapi.WlanGetNetworkBssList
WlanGetNetworkBssList.argtypes = (HANDLE, POINTER(GUID),POINTER(GUID),POINTER(GUID), c_bool, c_void_p,
POINTER(POINTER(WLAN_BSS_LIST)))
WlanGetNetworkBssList.restype = DWORD
WlanFreeMemory = wlanapi.WlanFreeMemory
WlanFreeMemory.argtypes = [c_void_p]
WlanScan = wlanapi.WlanScan
WlanScan.argtypes = (HANDLE, POINTER(GUID),c_void_p,c_void_p, c_void_p)
WlanScan.restype = DWORD
def get_interface():
NegotiatedVersion = DWORD()
ClientHandle = HANDLE()
ret = WlanOpenHandle(1, None, byref(NegotiatedVersion), byref(ClientHandle))
if ret != ERROR_SUCCESS:
exit(FormatError(ret))
# find all wireless network interfaces
pInterfaceList = pointer(WLAN_INTERFACE_INFO_LIST())
ret = WlanEnumInterfaces(ClientHandle, None, byref(pInterfaceList))
if ret != ERROR_SUCCESS:
exit(FormatError(ret))
try:
ifaces = customresize(pInterfaceList.contents.InterfaceInfo,
pInterfaceList.contents.NumberOfItems)
# find each available network for each interface
for iface in ifaces:
#print "Interface: %s" % (iface.strInterfaceDescription)
interface = iface.strInterfaceDescription
finally:
WlanFreeMemory(pInterfaceList)
return interface
class MAC_BSSID_POWER:
"""Classe para os valores retirados"""
def __init__(self, mac, bssid):
self.mac = str(mac)
self.bssid = str(bssid)
self.valores = []
def addPower(self,power):
self.valores.append(int(power))
def getBssid(self):
return self.bssid
def getPowers(self):
return self.valores
def getMac(self):
return self.mac
def get_BSSI():
BSSI_Values={}
NegotiatedVersion = DWORD()
ClientHandle = HANDLE()
ret = WlanOpenHandle(1, None, byref(NegotiatedVersion), byref(ClientHandle))
if ret != ERROR_SUCCESS:
exit(FormatError(ret))
# find all wireless network interfaces
pInterfaceList = pointer(WLAN_INTERFACE_INFO_LIST())
ret = WlanEnumInterfaces(ClientHandle, None, byref(pInterfaceList))
if ret != ERROR_SUCCESS:
exit(FormatError(ret))
try:
ifaces = customresize(pInterfaceList.contents.InterfaceInfo,
pInterfaceList.contents.NumberOfItems)
# find each available network for each interface
for iface in ifaces:
# print "Interface: %s" % (iface.strInterfaceDescription)
pAvailableNetworkList2 = pointer(WLAN_BSS_LIST())
ret2 = WlanGetNetworkBssList(ClientHandle,
byref(iface.InterfaceGuid),
None,
None,True,None,
byref(pAvailableNetworkList2))
if ret2 != ERROR_SUCCESS:
exit(FormatError(ret2))
try:
retScan = WlanScan(ClientHandle,byref(iface.InterfaceGuid),None,None,None)
if retScan != ERROR_SUCCESS:
exit(FormatError(retScan))
avail_net_list2 = pAvailableNetworkList2.contents
networks2 = customresize(avail_net_list2.NetworkBSS,
avail_net_list2.NumberOfItems)
for network in networks2:
SSID = str(network.dot11Ssid.SSID[:network.dot11Ssid.SSIDLength])
BSSID = ':'.join('%02x' % b for b in network.dot11Bssid).upper()
signal_strength = str(network.lRssi)
# print "SSID: " + SSID + " BSSID: "+ BSSID+ " SS: "+signal_strength
BSSI_Values[BSSID] = [SSID,signal_strength]
#print "Total "+str(len(networks2))
#print BSSI_Values
finally:
WlanFreeMemory(pAvailableNetworkList2)
WlanCloseHandle(ClientHandle,None)
finally:
WlanFreeMemory(pInterfaceList)
return BSSI_Values
def get_BSSI_times_and_total_seconds(times,seconds):
BSSI_to_return = {}
for i in range(0,seconds*times):
time_to_sleep = float(1.0/times)
time.sleep(time_to_sleep)
got_bssi_temp = get_BSSI()
for bssi in got_bssi_temp:
if not BSSI_to_return.get(bssi):
BSSI_to_return[bssi] = MAC_BSSID_POWER(bssi,got_bssi_temp[bssi][0])
BSSI_to_return[bssi].addPower( got_bssi_temp[bssi][1] )
#BSSI_to_return[bssi] = [got_bssi_temp[bssi][1]]
else:
BSSI_to_return[bssi].addPower( got_bssi_temp[bssi][1] )
#BSSI_to_return[bssi].append(got_bssi_temp[bssi][1])
print "Medicao "+str(i)+" de "+str(seconds*times)
print BSSI_to_return
return BSSI_to_return
if __name__ == '__main__':
#print get_interface()
import time
test = get_BSSI()
for i in range(0,10):
time.sleep(0.5)
oldTest = test
test = get_BSSI()
print "Teste: "+str(i)
if oldTest == test:
print "IGUAL"
else:
print "DIFERENTE"
print test
print "End"
@fmark 我只想对这篇精彩的帖子表示非常感谢。在我的工作中,我一直在尝试从 Windows 中连接的 AP 获取 RSSI,您应该非常感谢我终于完成了它。我目前正在列出所有 AP,但我正在修改它。我想对您的代码提出建议。我对 C 或 Python CTypes 模块不是很有经验,但我想我可能发现了一个可能的错误。我真的不确定它有什么不同,但我注意到:
您可以像这样定义枚举:
DOT11_BSS_TYPE = c_uint
(dot11_BSS_type_infrastructure,
dot11_BSS_type_independent,
dot11_BSS_type_any) = map(DOT11_BSS_TYPE, xrange(1, 4))
但是其他时候你定义了一些非常相似的东西:
DOT11_PHY_TYPE = c_uint
dot11_phy_type_unknown = 0
dot11_phy_type_any = 0
dot11_phy_type_fhss = 1
dot11_phy_type_dsss = 2
dot11_phy_type_irbaseband = 3
dot11_phy_type_ofdm = 4
dot11_phy_type_hrdsss = 5
dot11_phy_type_erp = 6
dot11_phy_type_ht = 7
dot11_phy_type_IHV_start = 0x80000000
dot11_phy_type_IHV_end = 0xffffffff
我认为第二个片段应该像第一个那样建模,但我可能错了。这是我的想法:
DOT11_PHY_TYPE = c_uint
(dot11_phy_type_unknown,
dot11_phy_type_any,
dot11_phy_type_fhss,
dot11_phy_type_dsss,
dot11_phy_type_irbaseband,
dot11_phy_type_ofdm,
dot11_phy_type_hrdsss,
dot11_phy_type_erp,
dot11_phy_type_ht,
dot11_phy_type_IHV_start,
dot11_phy_type_IHV_end) = map(DOT11_PHY_TYPE,
[0,0,1,2,3,4,
5,6,7,0x80000000,
0xffffffff])
这样,这些值将正确映射到 DOT11_PHY_TYPE。也许我完全错了,但对于像我这样的未来人,我只是希望这里偶然发现的任何东西都是正确的:) 再次感谢@fmark。