ACCEPT(3XNET)ACCEPT(3XNET)NAMEaccept - accept a new connection on a socket
cc [ flag ... ] file ... -lxnet [ library ... ]
int accept(int socket, struct sockaddr *restrict address,
socklen_t *restrict address_len);
The accept() function extracts the first connection on the queue of
pending connections, creates a new socket with the same socket type
protocol and address family as the specified socket, and allocates a
new file descriptor for that socket.
The function takes the following arguments:
Specifies a socket that was created with socket(3XNET),
has been bound to an address with bind(3XNET), and has
issued a successful call to listen(3XNET).
Either a null pointer, or a pointer to a sockaddr struc‐
ture where the address of the connecting socket will be
Points to a socklen_t which on input specifies the
length of the supplied sockaddr structure, and on output
specifies the length of the stored address.
If address is not a null pointer, the address of the peer for the
accepted connection is stored in the sockaddr structure pointed to by
address, and the length of this address is stored in the object pointed
to by address_len.
If the actual length of the address is greater than the length of the
supplied sockaddr structure, the stored address will be truncated.
If the protocol permits connections by unbound clients, and the peer is
not bound, then the value stored in the object pointed to by address is
If the listen queue is empty of connection requests and O_NONBLOCK is
not set on the file descriptor for the socket, accept() will block
until a connection is present. If the listen(3XNET) queue is empty of
connection requests and O_NONBLOCK is set on the file descriptor for
the socket, accept() will fail and set errno to EAGAIN or EWOULDBLOCK.
The accepted socket cannot itself accept more connections. The origi‐
nal socket remains open and can accept more connections.
When a connection is available, select(3C) will indicate that the file
descriptor for the socket is ready for reading.
Upon successful completion, accept() returns the nonnegative file
descriptor of the accepted socket. Otherwise, −1 is returned and errno
is set to indicate the error.
The accept() function will fail if:
O_NONBLOCK is set for the socket file descriptor and no
connections are present to be accepted.
The socket argument is not a valid file descriptor.
A connection has been aborted.
The address or address_len parameter can not be
accessed or written.
The accept() function was interrupted by a signal that
was caught before a valid connection arrived.
The socket is not accepting connections.
OPEN_MAX file descriptors are currently open in the
The maximum number of file descriptors in the system
are already open.
The socket argument does not refer to a socket.
The socket type of the specified socket does not sup‐
port accepting connections.
The accept() function may fail if:
No buffer space is available.
There was insufficient memory available to complete the
There was insufficient STREAMS resources available to com‐
plete the operation.
A protocol error has occurred; for example, the STREAMS pro‐
tocol stack has not been initialized.
See attributes(5) for descriptions of the following attributes:
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
│Interface Stability │ Standard │
│MT-Level │ MT-Safe │
SEE ALSObind(3XNET), connect(3XNET), listen(3XNET), socket(3XNET),
Nov 1, 2003 ACCEPT(3XNET)