gethostbyname - Sockets 2 Reference

gethostbyname

The Windows Sockets gethostbyname function gets host information corresponding to a hostname.

struct hostent FAR * gethostbyname (

const char FAR * name
);

Parameters
name

[out] A pointer to the null terminated name of the host.

Remarks
gethostbyname returns a pointer to a hostent structure. The contents of this structure correspond to the hostname name.

The pointer which is returned points to a structure which is allocated by Windows Sockets. The application must never attempt to modify this structure or to free any of its components. Furthermore, only one copy of this structure is allocated per thread, and so the application should copy any information which it needs before issuing any other Windows Sockets function calls.

gethostbyname does not resolve IP address strings passed to it. Such a request is treated exactly as if an unknown host name were passed. An application with an IP address string to resolve should use inet_addr to convert the string to an IP address, then gethostbyaddr to obtain the hostent structure.

gethostbyname will resolve the string returned by a successful call to gethostname.

Return Values
If no error occurs, gethostbyname returns a pointer to the hostent structure described above. Otherwise, it returns a NULL pointer and a specific error number 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 failure.
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.
WSAEFAULT	The name argument is not a valid part of the user address space.
WSAEINTR	The (blocking) call was canceled through WSACancelBlockingCall.

See Also
gethostbyaddr, WSAAsyncGetHostByName

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