ACCEPT(2) — System Interface Manual — System Calls

NAME

accept − accept a connection on a socket

SYNOPSIS

#include <sys/socket.h>

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

DESCRIPTION

The argument s is a socket which has been created with socket(2), bound to an address with bind(2) and is listening for connections after a listen(2). The first queued connection is extracted from the queue with accept.

The argument addr is a result indicating the address of the entity which connected, as known to the communications layer. The exact format of the addr parameter is determined by the address family 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 the 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 descriptor.

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 writeable part of the user address space.

Museum