|| Linux Programmer's Manual
NAME getpeername - get name of connected peer socket
, struct sockaddr *
, socklen_t *
() returns the address of the peer connected to the socket
, in the buffer pointed to by
argument should be initialized to indicate the amount of space pointed to by
. On return it contains the actual size of the name returned (in bytes). The name is truncated if the buffer provided is too small.
The returned address is truncated if the buffer provided is too small; in this case,
will return a value greater than was supplied to the call.
RETURN VALUE On success, zero is returned. On error, -1 is returned, and
errno is set appropriately.
sockfd is not a valid descriptor.
addr argument points to memory not in a valid part of the process address space.
addrlen is invalid (e.g., is negative).
Insufficient resources were available in the system to perform the operation.
The socket is not connected.
sockfd is a file, not a socket.
CONFORMING TO SVr4, 4.4BSD (the
getpeername() function call first appeared in 4.2BSD), POSIX.1-2001.
The third argument of
() is in reality an
(and this is what 4.x BSD and libc4 and libc5 have). Some POSIX confusion resulted in the present
, also used by glibc. See also
For stream sockets, once a
(2) has been performed, either socket can call
() to obtain the address of the peer socket. On the other hand, datagram sockets are connectionless. Calling
(2) on a datagram socket merely sets the peer address for outgoing datagrams sent with
(2). The caller of
(2) can use
() to obtain the peer address that it earlier set for the socket. However, the peer socket is unaware of this information, and calling
() on the peer socket will return no useful information (unless a
(2) call was also executed on the peer). Note also that the receiver of a datagram can obtain the address of the sender when using
COLOPHON This page is part of release 3.53 of the Linux
man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.