accept(3socket)

1accept(3SOCKET)            Sockets Library Functions           accept(3SOCKET)
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NAME

6       accept - accept a connection on a socket
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SYNOPSIS

9       cc [ flag ... ] file ... -lsocket  -lnsl  [ library ... ]
10       #include <sys/types.h>
11       #include <sys/socket.h>
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13       int accept(int s, struct sockaddr *addr, socklen_t *addrlen);
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DESCRIPTION

17       The  argument  s is a socket that has been created with socket(3SOCKET)
18       and bound to an address with bind(3SOCKET), and that is  listening  for
19       connections  after  a  call  to  listen(3SOCKET). The accept() function
20       extracts the first connection on the queue of pending connections, cre‐
21       ates  a  new  socket with the properties of s, and allocates a new file
22       descriptor, ns, for the socket. If no pending connections  are  present
23       on  the  queue  and  the socket is not marked as non-blocking, accept()
24       blocks the caller until a connection  is  present.  If  the  socket  is
25       marked  as  non-blocking  and no pending connections are present on the
26       queue, accept() returns an error  as  described  below.   The  accept()
27       function  uses  the  netconfig(4)  file to determine the STREAMS device
28       file name associated with s.  This is the device on which  the  connect
29       indication  will  be accepted. The accepted socket, ns, is used to read
30       and write data to and from the socket that connected to ns. It  is  not
31       used  to  accept more connections. The original socket (s) remains open
32       for accepting further connections.
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35       The argument addr is a result parameter that  is  filled  in  with  the
36       address  of  the connecting entity as it is known to the communications
37       layer. The exact format of the addr  parameter  is  determined  by  the
38       domain in which the communication occurs.
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41       The  argument  addrlen  is a value-result parameter. Initially, it con‐
42       tains the amount of space pointed to by addr; on return it contains the
43       length in bytes of the address returned.
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46       The  accept() function is used with connection-based socket types, cur‐
47       rently with SOCK_STREAM.
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50       It is possible to select(3C) or poll(2) a socket for the purpose of  an
51       accept() by selecting or polling it for a read. However, this will only
52       indicate when a connect indication is pending; it is still necessary to
53       call accept().
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RETURN VALUES

56       The accept() function returns −1 on error. If it succeeds, it returns a
57       non-negative integer that is a descriptor for the accepted socket.
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ERRORS

60       accept() will fail if:
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62       EBADF           The descriptor is invalid.
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65       ECONNABORTED    The remote  side  aborted  the  connection  before  the
66                       accept() operation completed.
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69       EFAULT          The addr parameter or the addrlen parameter is invalid.
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72       EINTR           The accept() attempt was interrupted by the delivery of
73                       a signal.
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76       EMFILE          The per-process descriptor table is full.
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79       ENODEV          The protocol family and type corresponding to  s  could
80                       not be found in the netconfig file.
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83       ENOMEM          There  was  insufficient  user memory available to com‐
84                       plete the operation.
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87       ENOSR           There were insufficient STREAMS resources available  to
88                       complete the operation.
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91       ENOTSOCK        The descriptor does not reference a socket.
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94       EOPNOTSUPP      The referenced socket is not of type SOCK_STREAM.
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97       EPROTO          A protocol error has occurred; for example, the STREAMS
98                       protocol stack has not been initialized or the  connec‐
99                       tion has already been released.
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102       EWOULDBLOCK     The socket is marked as non-blocking and no connections
103                       are present to be accepted.
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ATTRIBUTES

107       See attributes(5) for descriptions of the following attributes:
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112       ┌─────────────────────────────┬─────────────────────────────┐
113       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
114       ├─────────────────────────────┼─────────────────────────────┤
115       │MT-Level                     │Safe                         │
116       └─────────────────────────────┴─────────────────────────────┘
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NAME

SYNOPSIS

DESCRIPTION

RETURN VALUES

ERRORS

ATTRIBUTES

SEE ALSO