MSDN

[joerbanno]

Hi,

I've just another question, it's Masm related.
I'm trying to access network interface information, like what network devices are presented, which of them are enabled and more.
I use the API GetIfTable returning me a

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MIB_IFTABLE  struct
   dwNumEntries DWORD 0
   table MIB_IFROW ANY_SIZE dup(<>)
MIB_IFTABLE  ENDS


The entry table is of type MIB_IFROW

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MIB_IFROW STRUCT
  wszName WORD MAX_INTERFACE_NAME_LEN dup(0)
  dwIndex DWORD 0
  dwType DWORD 0
  dwMtu DWORD 0
  dwSpeed DWORD 0
  dwPhysAddrLen DWORD 0
  bPhysAddr BYTE MAXLEN_PHYSADDR dup(0)
  .... abbreviated
  dwDescrLen DWORD 0
  bDescr BYTE MAXLEN_IFDESCR dup(0)
MIB_IFROW ENDS

The MSDN implements the wszName as unicode (16bits in windows) in the current implementation.
The MSDN says about wszName:

wszName A pointer to a Unicode string that contains the name of the interface

If that's correct shouldn't wszName not be a DWORD? :dazzled:

What's the word on this?
The funny thing is if I check the length of the wszName string with ucLen, I always end up with 0 :red

[jag]

A pointer is always a DWORD (well on x86 architecture.)
Normally in a string, each character is 8-bits ( 1 byte ) so each character can have 256 different values.
Unicode lets each character have 16-bits (2 bytes) so that each character can 65535 different values.

Your POINTER to the unicode string will still be a dword though the string structure differs.

[MichaelW]

From lprtrmib.h in the SDK:

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typedef struct _MIB_IFROW
{
    WCHAR   wszName[MAX_INTERFACE_NAME_LEN];
    DWORD    dwIndex;
    DWORD    dwType;
    DWORD    dwMtu;
    DWORD    dwSpeed;
...

wszName is a Unicode string, not a pointer. WCHAR is defined in the header files as an unsigned short, so for MASM it is a WORD, as it is defined in the MASM32 windows.inc.