gethostbyname
A version of this page is also available for
4/8/2010
This function retrieves host information corresponding to a host name from a host database.
Note
The gethostbyname function has been deprecated by the introduction of the getaddrinfo function. Developers who create Windows Sockets 2 applications are urged to use the getaddrinfo function instead of gethostbyname.
Syntax
struct hostent FAR* gethostbyname(
const char FAR* name
);
Parameters
- name
[out] Pointer to the null-terminated name of the host to resolve.
Return Value
If no error occurs, this function returns a pointer to the hostent structure. If an error occurs, it returns a NULL pointer, and a specific error number can be retrieved by calling WSAGetLastError.
The following table shows the possible error codes.
| Error code | Description |
|---|---|
WSANOTINITIALISED |
A successful WSAStartup call must occur before using this function. |
WSAENETDOWN |
The network subsystem has failed. |
WSAHOST_NOT_FOUND |
An authoritative answer host was not found. |
WSATRY_AGAIN |
A nonauthoritative host was not found, or the server failure. |
WSANO_RECOVERY |
A nonrecoverable error occurred. |
WSANO_DATA |
A valid name exists, but no data record of the requested type exists. |
WSAEINPROGRESS |
A blocking Winsock call is in progress, or the service provider is still processing a callback function. |
WSAEFAULT |
The name parameter is not a valid part of the user address space. |
WSAEINTR |
The socket was closed. |
Note
Japanese Version Winsock calls to get the machine IP address will fail if the machine name is entered in Japanese characters.
Remarks
This function returns a pointer to a hostent structure, which is a structure allocated by Windows Sockets. The hostent structure contains the results of a successful search for the host specified in the name parameter.
The application must never attempt to modify this structure or to free anything inside the structure.. Furthermore, only one copy of this structure is allocated per thread, so the application should copy any information it needs before issuing any other Windows Sockets function calls.
This function cannot resolve IP address strings passed to it. Such a request is treated exactly as if an unknown host name were passed. Use inet_addr to convert an IP address string to an actual IP address, then use another function, gethostbyaddr, to obtain the contents of the hostent structure.
The gethostbyname function resolves the string returned by a successful call to gethostname.
Requirements
| Header | winsock2.h |
| Library | Ws2.lib |
| Windows Embedded CE | Windows CE 1.0 and later |
| Windows Mobile | Windows Mobile Version 5.0 and later |
See Also
Reference
gethostbyaddr
gethostname
hostent
inet_addr
WSAGetLastError
WSAStartup