accept(3XNET) X/Open Networking Services Library Functions accept(3XNET)NAMEaccept - accept a new connection on a socket
SYNOPSIS
cc [ flag ... ] file ... -lxnet [ library ... ]
#include <sys/socket.h>
int accept(int socket, struct sockaddr *restrict address, socklen_t
*restrict address_len);
DESCRIPTION
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:
socket 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).
address Either a null pointer, or a pointer to a sockaddr
structure where the address of the connecting socket
will be returned.
address_len Points to a socklen_t which on input specifies the
length of the supplied sockaddr structure, and on out‐
put 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
unspecified.
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.
USAGE
When a connection is available, select(3C) will indicate that the file
descriptor for the socket is ready for reading.
RETURN VALUES
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.
ERRORS
The accept() function will fail if:
EAGAIN O_NONBLOCK is set for the socket file descrip‐
EWOULDBLOCK tor and no connections are present to be
accepted.
EBADF The socket argument is not a valid file
descriptor.
ECONNABORTED A connection has been aborted.
EFAULT The address or address_len parameter can not
be accessed or written.
EINTR The accept() function was interrupted by a sig‐
nal that was caught before a valid connection
arrived.
EINVAL The socket is not accepting connections.
EMFILE OPEN_MAX file descriptors are currently open in
the calling process.
ENFILE The maximum number of file descriptors in the
system are already open.
ENOTSOCK The socket argument does not refer to a socket.
EOPNOTSUPP The socket type of the specified socket does
not support accepting connections.
The accept() function may fail if:
ENOBUFS No buffer space is available.
ENOMEM There was insufficient memory available to com‐
plete the operation.
ENOSR There was insufficient STREAMS resources avail‐
able to complete the operation.
EPROTO A protocol error has occurred; for example, the
STREAMS protocol stack has not been initial‐
ized.
ATTRIBUTES
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),
attributes(5), standards(5)SunOS 5.10 1 Nov 2003 accept(3XNET)
