svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.
accept4(3c)
accept(3C) Standard C Library Functions accept(3C)
NAME
accept, accept4 - accept a new connection on a socket
SYNOPSIS
#include <sys/socket.h>
int accept(int socket, struct sockaddr *restrict address,
socklen_t *restrict address_len);
int accept4(int socket, struct sockaddr *restrict address,
socklen_t *restrict address_len, int flags);
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 A socket created with socket(3C), bound to an address
with bind(3C), and in the LISTEN state after a success‐
ful call to listen(3C).
address Either a null pointer, or a pointer to a sockaddr struc‐
ture 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 output
specifies the length of the stored address.
If address is not a null pointer, the address of the peer for the ac‐
cepted connection is stored in the sockaddr structure pointed to by ad‐
dress, 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() and accept4()
will block until a connection is present. If the listen(3C) queue is
empty of connection requests and O_NONBLOCK is set on the file descrip‐
tor for the socket, accept() and accept4() will fail and set errno to
EAGAIN or EWOULDBLOCK.
The accepted socket cannot itself accept more connections. The original
socket remains open and can accept more connections.
The accept4() function behaves like accept() but the accepting socket
does not inherit NDELAY and NONBLOCKING from the original socket, in‐
stead it will take the settings from the flags argument:
SOCK_NDELAY
As if O_NDELAY is set for the socket.
SOCK_NONBLOCK
As if O_NONBLOCK is set for the socket.
SOCK_NOSIGPIPE
No SIGPIPE will be sent on write when the remote connection was
closed; instead EPIPE is returned.
SOCK_CLOEXEC
The socket will be closed on exec() or spawn().
SOCK_CLOFORK
The socket will not be inherited by the child on fork() or spawn().
If both SOCK_NDELAY and SOCK_NONBLOCK are set, the socket will behave
as if only SOCK_NONBLOCK is set.
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() and accept4() return the nonnega‐
tive file descriptor of the accepted socket. Otherwise, −1 is returned
and errno is set to indicate the error.
ERRORS
The accept() and accept4() functions will fail if:
EAGAIN O_NONBLOCK is set for the socket file descriptor and no
EWOULDBLOCK 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 ac‐
cessed or written.
EINTR The accept() function was interrupted by a signal that
was caught before a valid connection arrived.
EINVAL The socket is not accepting connections.
EMFILE The per-process limit of file descriptors are already
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 sup‐
port accepting connections.
The accept() and accept4() functions may fail if:
ENOBUFS No buffer space is available.
ENOMEM There is insufficient memory available to complete the oper‐
ation.
ENOSR There are insufficient STREAMS resources available to com‐
plete the operation.
EPROTO A protocol error has occurred; for example, the STREAMS pro‐
tocol stack has not been initialized.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRIBUTE TYPEAT‐
TRIBUTE VALUE _ Interface StabilityCommitted _ MT-LevelAsync-Signal-
Safe _ StandardSee standards(7).
SEE ALSO
bind(3C), connect(3C), listen(3C), socket(3C), attributes(7), stan‐
dards(7)
HISTORY
The accept() function has been present since the initial release of So‐
laris.
The accept4() function was added to Oracle Solaris in the Solaris
11.4.0 release.
Oracle Solaris 11.4 2 Feb 2021 accept(3C)