RasEnumDevices

The RasEnumDevices function returns the name and type of all available RAS-capable devices.

DWORD RasEnumDevices(
  LPRASDEVINFO lpRasDevInfo,  // buffer to receive
                              //  information about RAS devices
  LPDWORD lpcb,               // size, in bytes, of the buffer
  LPDWORD lpcDevices          // receives the number of
                              //  entries written to the buffer
);

Parameters

lpRasDevInfo

Pointer to a buffer that receives an array of RASDEVINFO structures, one for each RAS-capable device. Before calling the function, set the dwSize member of the first RASDEVINFO structure in the buffer to sizeof(RASDEVINFO) to identify the version of the structure.

lpcb

Pointer to a variable that contains the size, in bytes, of the lpRasDevInfo buffer. On return, the function sets this variable to the number of bytes required to enumerate the devices.

To determine the required buffer size, call RasEnumDevices with the lpRasDevInfo parameter set to NULL and the variable pointed to by lpcb set to zero. The function returns the required buffer size in the variable pointed to by lpcb. (See sample code under Remarks section.)

lpcDevices

Pointer to a variable that the function sets to the number of RASDEVINFO structures written to the lpRasDevInfo buffer.

Return Values

If the function succeeds, the return value is zero.

If the function fails, the return value is a nonzero RAS error value or one of following error codes.

Remarks

The following sample code enumerates the devices on the current machine. The code initially calls RasEnumDevices with a lpRasDevInfo parameter of NULL, to obtain the size of the buffer that should be passed in. The code also sets the dwSize member of the first RASDEVINFO structure to sizeof(RASDEVINFO) to specify the version of the structure.

RasEnumDevices(NULL, &lpcb, &lpcDevices);
lpRasDevInfo = (LPRASDEVINFO) GlobalAlloc(GPTR, lpcb);
lpRasDevInfo->dwSize = sizeof(RASDEVINFO);
 
nRet = RasEnumDevices(lpRasDevInfo, &lpcb, &lpcDevices);
if (nRet != 0)
{
    printf("RasEnumDevices failed: Error %d", nRet);
}
else
{
    printf("The following RAS capable devices were found on this machine:\n\n");
    for (i=0; i < lpcDevices; i++)
    {
        printf("%s\n",lpRasDevInfo->szDeviceName);
        lpRasDevInfo++;
    }
}

Requirements

  Windows NT/2000: Requires Windows NT 4.0 or later.
  Windows 95/98: Requires Windows 95 OSR2 or later.
  Header: Declared in Ras.h.
  Library: Use Rasapi32.lib.
  Unicode: Implemented as Unicode and ANSI versions on Windows NT/2000.

See Also

Remote Access Service (RAS) Overview, Remote Access Service Functions, RASDEVINFO