SNMP Manager Programmer's Guide

Constructing and Interpreting Packets
SNMP Manager Programmer’s Guide–134249
5-23
SNMP_Bind_Null()
SNMP_Bind_Null()
This function associates a variable binding of type NULL with a packet previously
initialized with SNMP_Create_Request() or SNMP_Create_Trap(). Use this function to
bind all MIB variables in Get and GetNext PDUs or to bind a NULL MIB variable in Set
or Trap PDUs.
rcode
is a return integer indicating whether the call succeeded. A value of 0 indicates
success, and -1 indicates failure.
packet
is a pointer to an initialized request or trap packet.
index
is a zero-based index value indicating the position into which to bind the MIB
variable in a list of variable bindings. A value of 0 binds the variable at the front of
the list, 1 binds the variable into the second position, and so forth. The order in
which you assign variable bindings to a list is irrelevant. For example, if you have
two variable bindings, you can use an index value of 1 in the first SNMP_Bind_ call
and a value of 0 in the second call to bind the variables into the second and first
positions, respectively.
instance-count
is the number of components in the instance identifier whose value you supply in
instance-components. For example, an instance identifier of 1.2.3.4 has a
component count of 4.
instance-components
is a pointer to a structure of type OIDC_T that contains the instance identifier of the
variable binding.
The following example, taken from SNMPSET, binds an object with a null value to a
request packet. Related declarations include a global define and OID structure
declaration and several variables in the main block; the Manager Services define
MAX_OID_COUNT is used to set the number of elements in the OID component array
and the component count variable to 32. The variable named longform indicates that the
rcode = SNMP_Bind_Null(packet,
index,
instance-count,
instance-components);
int SNMP_Bind_Null(SNMP_PKT_T *packet,
int index,
int instance-count,
OIDC_T *instance-components);