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32 .\" @(#)accept.2 8.2 (Berkeley) 12/11/93
33 .\" $FreeBSD: src/lib/libc/sys/accept.2,v 1.10.2.11 2002/05/09 02:24:40 silby Exp $
40 .Nd accept a connection on a socket
47 .Fn accept "int s" "struct sockaddr *addr" "socklen_t *addrlen"
51 is a socket that has been created with
53 bound to an address with
55 and is listening for connections after a
60 extracts the first connection request
61 on the queue of pending connections, creates
62 a new socket with the same properties as
64 and allocates a new file descriptor
65 for the socket. If no pending connections are
66 present on the queue, and the socket is not marked
69 blocks the caller until a connection is present.
70 If the socket is marked non-blocking and no pending
71 connections are present on the queue,
73 returns an error as described below.
76 to accept more connections. The original socket
82 is a result parameter that is filled-in with
83 the address of the connecting entity,
84 as known to the communications layer.
85 The exact format of the
87 parameter is determined by the domain in which the communication
91 is a value-result parameter; it should initially contain the
92 amount of space pointed to by
94 on return it will contain the actual length (in bytes) of the
97 is used with connection-based socket types, currently with
102 a socket for the purposes of doing an
104 by selecting it for read.
106 For certain protocols which require an explicit confirmation,
113 as merely dequeueing the next connection
114 request and not implying confirmation.
115 Confirmation can be implied by a normal read or write on the new
116 file descriptor, and rejection can be implied by closing the
119 For some applications, performance may be enhanced by using an
121 to pre-process incoming connections.
123 The call returns \-1 on error. If it succeeds, it returns a non-negative
124 integer that is a descriptor for the accepted socket.
131 The descriptor is invalid.
135 operation was interrupted.
137 The per-process descriptor table is full.
139 The system file table is full.
141 The descriptor references a file, not a socket.
144 has not been called on the socket descriptor.
148 parameter is not in a writable part of the
150 .It Bq Er EWOULDBLOCK
151 The socket is marked non-blocking and no connections
152 are present to be accepted.
153 .It Bq Er ECONNABORTED
154 A connection arrived, but it was closed while waiting
158 .Xr accept_filter 9 ,