# GET command

`pysnmp.hlapi.``getCmd`(snmpEngine, authData, transportTarget, contextData, *varBinds, **options)

  Creates a generator to perform one or more SNMP GET queries.

  On each iteration, new SNMP GET request is send (RFC 1905#section-4.2.1). The iterator blocks waiting for response to arrive or error to occur.

  Parameters

    - snmpEngine (`SnmpEngine`) – Class instance representing SNMP engine.

    - authData (`CommunityData` or `UsmUserData`) – Class instance representing SNMP credentials.

    - transportTarget (`UdpTransportTarget` or `Udp6TransportTarget`) – Class instance representing transport type along with SNMP peer address.

    - contextData (`ContextData`) – Class instance representing SNMP ContextEngineId and ContextName values.

    - *varBinds (`ObjectType`) – One or more class instances representing MIB variables to place into SNMP request.

  Other Parameters

    **options –

    Request options:

    > - lookupMib - load MIB and resolve response MIB variables at the cost of slightly reduced performance. Default is True.

  Yields

    - errorIndication (str) – True value indicates SNMP engine error.

    - errorStatus (str) – True value indicates SNMP PDU error.

    - errorIndex (int) – Non-zero value refers to varBinds[errorIndex-1]

    - varBinds (tuple) – A sequence of `ObjectType` class instances representing MIB variables returned in SNMP response.

  Raises

    PySnmpError – Or its derivative indicating that an error occurred while performing SNMP operation.

  Notes

  The getCmd generator will be exhausted immidiately unless a new sequence of varBinds are send back into running generator (supported since Python 2.6).

  Examples

      >>> from pysnmp.hlapi import *
      >>> g = getCmd(SnmpEngine(),
      ...            CommunityData('public'),
      ...            UdpTransportTarget(('demo.snmplabs.com', 161)),
      ...            ContextData(),
      ...            ObjectType(ObjectIdentity('SNMPv2-MIB', 'sysDescr', 0)))
      >>> next(g)
      (None, 0, 0, [ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.1.0')), DisplayString('SunOS zeus.snmplabs.com 4.1.3_U1 1 sun4m'))])
      >>>