getprotobyname function (winsock.h)

Article
02/22/2024

The getprotobyname function retrieves the protocol information corresponding to a protocol name.

Syntax

protoent * getprotobyname(
  [in] const char *name
);

Parameters

[in] name

Pointer to a null-terminated protocol name.

Return value

If no error occurs, getprotobyname returns a pointer to the protoent. Otherwise, it returns a null pointer and a specific error number can be retrieved by calling WSAGetLastError.

Error code	Meaning
WSANOTINITIALISED	A successful WSAStartup call must occur before using this function.
WSAENETDOWN	The network subsystem has failed.
WSAHOST_NOT_FOUND	Authoritative answer protocol not found.
WSATRY_AGAIN	A nonauthoritative protocol not found, or server failure.
WSANO_RECOVERY	Nonrecoverable errors, the protocols database is not accessible.
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 parameter is not a valid part of the user address space.
WSAEINTR	A blocking Windows Socket 1.1 call was canceled through WSACancelBlockingCall.

Remarks

The getprotobyname function returns a pointer to the protoent structure containing the name(s) and protocol number that correspond to the protocol specified in the name parameter. All strings are null-terminated. The protoent structure is allocated by the Windows Sockets library. An application must never attempt to modify this structure or to free any of its components. Furthermore, like hostent, only one copy of this structure is allocated per thread, so the application should copy any information that it needs before issuing any other Windows Sockets function calls.

Windows Phone 8: This function is supported for Windows Phone Store apps on Windows Phone 8 and later.

Windows 8.1 and Windows Server 2012 R2: This function is supported for Windows Store apps on Windows 8.1, Windows Server 2012 R2, and later.

Requirements

Requirement	Value
Minimum supported client	Windows 8.1, Windows Vista [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2003 [desktop apps \| UWP apps]
Target Platform	Windows
Header	winsock.h (include Winsock2.h)
Library	Ws2_32.lib
DLL	Ws2_32.dll