SnmpStrToOid function (winsnmp.h)

[SNMP is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions. Instead, use Windows Remote Management, which is the Microsoft implementation of WS-Man.]

The WinSNMP SnmpStrToOid function converts the dotted numeric string format of an SNMP object identifier, for example, "", to its internal binary representation.


  [in]  LPCSTR   string,
  [out] smiLPOID dstOID


[in] string

Pointer to a null-terminated object identifier string to convert.

[out] dstOID

Pointer to an smiOID structure that receives the converted value.

Return value

If the function succeeds, the return value is the number of subidentifiers in the converted object identifier. This number is also the value of the len member of the smiOID structure pointed to by the dstOID parameter.

If the function fails, the return value is SNMPAPI_FAILURE. To get extended error information, call SnmpGetLastError specifying a NULL value in its session parameter. The SnmpGetLastError function can return one of the following errors.

Return code Description
The SnmpStartup function did not complete successfully.
An error occurred during memory allocation.
The string parameter is invalid. For additional information, see the following Remarks section.
An unknown or undefined error occurred.


The WinSNMP application must call the SnmpFreeDescriptor function to free resources allocated for the ptr member of the smiOID structure pointed to by the dstOID parameter. On input, SnmpFreeDescriptor ignores the members of this smiOID structure. The Microsoft WinSNMP implementation overwrites the smiOID members if the function completes successfully.

The SnmpStrToOid function fails and returns the SNMPAPI_OID_INVALID error code if the string parameter meets one of the following conditions:

  • Is not null-terminated.
  • Is not the textual form of a valid object identifier.
  • Is insufficient in length; all object identifiers must have two subidentifiers.
  • Exceeds the MAXOBJIDSTRSIZE of 1408 bytes.
For additional information, see WinSNMP Data Management Concepts and Freeing WinSNMP Descriptors.


Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header winsnmp.h
Library Wsnmp32.lib
DLL Wsnmp32.dll

See also


WinSNMP Functions

WinSNMP API Overview