accept - accept a connection on a socket
int accept (int s, struct sockaddr *addr, int *addrlen);
The argument s is a socket that has been created with socket(2), bound to
an address with bind(2), and is listening for connections after a
listen(2). Accept extracts the first connection on the queue of pending
connections, creates a new socket with the same properties of s and
allocates a new file descriptor for the socket. If no pending
connections are present on the queue, and the socket is not marked as
non-blocking, accept blocks the caller until a connection is present. If
the socket is marked non-blocking and no pending connections are present
on the queue, accept returns an error as described below. The accepted
socket may not be used to accept more connections. The original socket s
If addr is non-zero, it is a result parameter that is filled in with the
address of the connecting entity, as known to the communications layer.
The exact format of the addr parameter is determined by the domain in
which the communication is occurring. The addrlen is a value-result
parameter. It should initially contain the amount of space pointed to by
addr; on return it will contain the actual length (in bytes) of the
address returned. If addr is zero, addrlen is ignored.
This call is used with connection-based socket types, currently with
It is possible to select(2) a socket for the purposes of doing an accept
by selecting it for read.
The call returns -1 on error. If it succeeds, it returns a non-negative
integer that is a descriptor for the accepted socket.
The accept will fail if:
[EBADF] The descriptor is invalid.
[ENOTSOCK] The descriptor references a file, not a socket.
[EOPNOTSUPP] The referenced socket is not of type SOCK_STREAM.
[EFAULT] The addr or addrlen parameter is not in a writable
part of the user address space.
[EWOULDBLOCK] The socket is marked non-blocking and no connections
are present to be accepted.
[EMFILE] The per-process descriptor table is full.
[ENFILE] The system file table is full.
bind(2), connect(2), listen(2), select(2), socket(2)
ABI-compliant versions of the above call can be obtained from
When used with a socket of type AF_UNIX, this call does not return a
valid remote address, unless the remote end was explicitly bound to a
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