gethostbyaddr

The Windows Sockets gethostbyaddr function retrieves the host information corresponding to a network address.

struct HOSTENT FAR * gethostbyaddr (
  const char FAR * addr,  
  int len,                
  int type                
);
 

Parameters

addr
[in] A pointer to an address in network byte order.
len
[in] The length of the address.
type
[in] The type of the address.

Remarks

The gethostbyaddr function returns a pointer to the HOSTENT structure that contains the name and address corresponding to the given network address. All strings are null-terminated.

Return Values

If no error occurs, gethostbyaddr returns a pointer to the HOSTENT structure. Otherwise, it returns a NULL pointer, and a specific error code can be retrieved by calling WSAGetLastError.

Error Codes

WSANOTINITIALISED A successful WSAStartup must occur before using this function.
WSAENETDOWN The network subsystem has failed.
WSAHOST_NOT_FOUND Authoritative Answer Host not found.
WSATRY_AGAIN Non-Authoritative Host not found, or server failed.
WSANO_RECOVERY Nonrecoverable error occurred.
WSANO_DATA Valid name, no data record of requested type.
WSAEINPROGRESS A blocking Windows Sockets 1.1 call is in progress, or the service provider is still processing a callback function.
WSAEAFNOSUPPORT The type specified is not supported by the Windows Sockets implementation.
WSAEFAULT The addr parameter is not a valid part of the user address space, or the len parameter is too small.
WSAEINTR A blocking Windows Socket 1.1 call was canceled through WSACancelBlockingCall.

QuickInfo

  Windows NT: Yes
  Windows: Yes
  Windows CE: Use version 1.0 and later.
  Header: Declared in winsock2.h.
  Import Library: Link with ws2_32.lib.

See Also

gethostbyname, HOSTENT, WSAAsyncGetHostByAddr