NAME
accept - accept a connection on a socket

SYNOPSIS
#include <sys/types.h>
#include <sys/socket.h>

ns = accept(s, addr, addrlen)
int ns, s;
struct sockaddr *addr;
int *addrlen;

DESCRIPTION
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, ns, 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,
ns, may not be used to accept more connections. The original
socket s remains open.

The argument addr 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. This call is used with
connection-based socket types, currently with SOCK_STREAM.

It is possible to select(2) a socket for purposes of doing an
accept by selecting it for read.

RETURN VALUE
The call returns -1 on error. If it succeeds, it returns a non-
negative integer that is a descriptor for the accepted socket.

ERRORS
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 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.

SEE ALSO
bind(2), connect(2), listen(2), select(2), socket(2)