getpeername - Gets the name of the peer socket
struct sockaddr *address,
socklen_t *address_len );
[XNS4.0] The definition of the getpeername() function in
XNS4.0 uses a size_t data type instead of a socklen_t data
type as specified in XNS5.0 (the previous definition).
[Tru64 UNIX] The following definition of the getpeername()
function does not conform to current standards and
is supported only for backward compatibility (see standards(5)). int getpeername(
struct sockaddr *address,
int *address_len );
Interfaces documented on this reference page conform to
industry standards as follows:
getpeername(): XNS4.0, XNS5.0
Refer to the standards(5) reference page for more information
about industry standards and associated tags.
Specifies the descriptor number of a connected socket.
Points to a sockaddr structure, the format of which is
determined by the domain and by the behavior requested for
the socket. The sockaddr structure is an overlay for a
sockaddr_in, sockaddr_un, sockaddr_in6, or sockaddr_storage
structure, depending on which of the supported address
families is active.
[Tru64 UNIX] If the compile-time option _SOCKADDR_LEN
is defined before the sys/socket.h header
file is included, the sockaddr structure takes
4.4BSD behavior, with a field for specifying the
length of the socket address. Otherwise, the
default 4.3BSD sockaddr structure is used, with the
length of the socket address assumed to be 14 bytes
If _SOCKADDR_LEN is defined, the 4.3BSD sockaddr
structure is defined with the name osockaddr.
Specifies the length of the sockaddr structure
pointed to by the address parameter.
The getpeername() function retrieves the name of the peer
socket connected to the specified socket.
If the actual length of the address is greater than the
length of the sockaddr structure, the address is truncated.
If the protocol permits connections by unbound clients and
the peer is unbound, the value pointed to by address is
A process created by another process can inherit open
sockets, but may need to identify the addresses of the
sockets it has inherited. The getpeername() function
allows a process to retrieve the address of the peer
socket at the remote end of the socket connection.
The getpeername() function operates only on connected
A process can use the getsockname() function to retrieve
the local address of a socket.
[Tru64 UNIX] When compiled in the X/Open UNIX environment
or the POSIX.1g socket environment, calls to the getpeername()
function are internally renamed by prepending _E to
the function name. When you are debugging a module that
includes the getpeername() function and for which
_XOPEN_SOURCE_EXTENDED or _POSIX_PII_SOCKET has been
defined, use _Egetpeername to refer to the getpeername()
call. See standards(5) for further information.
Upon successful completion, a value of 0 (zero) is
returned and the address parameter holds the address of
the peer socket. If the getpeername() function fails, a
value of -1 is returned and errno is set to indicate the
If the getpeername() function fails, errno may be set to
one of the following values: The socket parameter is not
valid. The address or address_len parameter is not in a
readable OR writable part of the user address space. The
socket has been shut down. Insufficient resources were
available in the system to complete the call. The available
STREAMS resources were insufficient for the operation
to complete. The socket is not connected. The socket
parameter refers to a file, not a socket. The operation
is not supported for the socket protocol.
Functions: accept(2), bind(2), getsockname(2), socket(2).
Network Programmer's Guide
[ Back ]