getpeername(2)getpeername(2)NAMEgetpeername - get address of connected peer
SYNOPSIS
AF_CCITT Only
UNIX 03 Only (X/Open Sockets)
Obsolescent UNIX 95 Only (X/Open Sockets)
DESCRIPTION
returns the address of the peer socket connected to the socket indi‐
cated by s, where s is a socket descriptor. addr points to a socket
address structure in which this address is returned. addrlen points to
a variable that should be initialized to indicate the size of the
address structure. On return, the variable contains the actual size of
the address returned (in bytes). If addr does not point to enough
space to contain the whole address of the peer, only the first addrlen
bytes of the address are returned.
AF_CCITT Only
The addr struct contains the X.25 addressing information of the remote
peer socket connected to socket s. However, the field of the addr
struct contains the name of the local X.25 interface through which the
call arrived.
X/Open Sockets Compilation Environment
See xopen_networking(7).
RETURN VALUE
Upon successful completion, returns 0; otherwise it returns −1 and sets
to indicate the error.
ERRORS
fails if any of the following conditions are encountered:
s is not a valid file descriptor.
s is a valid file descriptor, but it is not a
socket.
The socket is not connected.
No buffer space is available
to perform the operation.
addr or addrlen are not valid pointers.
The socket has been shut down.
The operation was interrupted by a signal.
Application needs to retry the operation to get
the address of peer socket.
Not all possible values are documented in this manpage due to dependen‐
cies from the underlying protocol modules.
OBSOLESCENCE
Currently, the and types are the same size. This is compatible with
the UNIX 95 and UNIX 03 profiles. However, in a future release, might
be a different size. In that case, passing a pointer will evoke com‐
pile-time warnings, which must be corrected in order for the applica‐
tion to behave correctly. Applications that use now, where appropri‐
ate, will avoid such migration problems. On the other hand, applica‐
tions that need to be portable to the UNIX 95 profile should follow the
X/Open specification (see xopen_networking(7)).
WARNINGS
Linking binary objects compiled to specification and binary objects
compiled to specification to the same executable may result in unex‐
pected behavior, including application abnormal termination and unex‐
pected socket errors. See xopen_networking(7) for details and remedy.
FUTURE DIRECTION
Currently, the default behavior is the however, it might be changed to
in a future release. At that time, any behavior that is incompatible
with might be obsoleted. Applications that conform to the X/Open spec‐
ification now will avoid migration problems (see xopen_networking(7)).
AUTHOR
was developed by HP and the University of California, Berkeley.
SEE ALSObind(2), socket(2), getsockname(2), thread_safety(5), inet(7F),
xopen_networking(7).
STANDARDS CONFORMANCEgetpeername(2)
