socketpair(3xnet)

1socketpair(3XNET)X/Open Networking Services Library Functionssocketpair(3XNET)
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NAME

6       socketpair - create a pair of connected sockets
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SYNOPSIS

9       cc [ flag ... ] file ... -lxnet [ library ... ]
10       #include <sys/socket.h>
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12       int socketpair(int domain, int type, int protocol, int socket_vector[2]);
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DESCRIPTION

16       The  socketpair() function creates an unbound pair of connected sockets
17       in a specified domain, of a specified type, under the protocol  option‐
18       ally  specified  by the protocol argument.  The two sockets are identi‐
19       cal. The file descriptors used in referencing the created  sockets  are
20       returned in socket_vector0 and socket_vector1.
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23       The  type  argument  specifies  the  socket  type, which determines the
24       semantics of communications over the socket.   The  socket  types  sup‐
25       ported  by  the  system  are implementation-dependent.  Possible socket
26       types include:
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28       SOCK_STREAM       Provides sequenced, reliable, bidirectional,  connec‐
29                         tion-mode  byte  streams, and may provide a transmis‐
30                         sion mechanism for out-of-band data.
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33       SOCK_DGRAM        Provides datagrams,  which  are  connectionless-mode,
34                         unreliable messages of fixed maximum length.
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37       SOCK_SEQPACKET    Provides  sequenced, reliable, bidirectional, connec‐
38                         tion-mode transmission path for  records.   A  record
39                         can  be  sent using one or more output operations and
40                         received using one or more input  operations,  but  a
41                         single  operation  never  transfers part of more than
42                         one record.  Record boundaries  are  visible  to  the
43                         receiver via the MSG_EOR flag.
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47       If  the  protocol argument is non-zero, it must specify a protocol that
48       is supported by the address family.  The  protocols  supported  by  the
49       system are implementation-dependent.
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52       The  process may need to have appropriate privileges to use the socket‐
53       pair() function or to create some sockets.
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PARAMETERS

56       domain           Specifies the communications domain in which the sock‐
57                        ets are to be created.
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60       type             Specifies the type of sockets to be created.
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63       protocol         Specifies  a  particular  protocol to be used with the
64                        sockets. Specifying a protocol  of  0  causes  socket‐
65                        pair()  to  use an unspecified default protocol appro‐
66                        priate for the requested socket type.
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69       socket_vector    Specifies a 2-integer array to hold the file  descrip‐
70                        tors of the created socket pair.
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USAGE

74       The  documentation for specific address families specifies which proto‐
75       cols each address family supports.  The documentation for specific pro‐
76       tocols specifies which socket types each protocol supports.
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79       The  socketpair()  function  is used primarily with UNIX domain sockets
80       and need not be supported for other domains.
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RETURN VALUES

83       Upon successful completion, this function returns 0.  Otherwise, −1  is
84       returned and errno is set to indicate the error.
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ERRORS

87       The socketpair() function will fail if:
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89       EAFNOSUPPORT       The  implementation  does  not support the specified
90                          address family.
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93       EMFILE             No more file  descriptors  are  available  for  this
94                          process.
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97       ENFILE             No  more file descriptors are available for the sys‐
98                          tem.
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101       EOPNOTSUPP         The specified protocol does not permit  creation  of
102                          socket pairs.
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105       EPROTONOSUPPORT    The protocol is not supported by the address family,
106                          or the protocol is not supported by the  implementa‐
107                          tion.
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110       EPROTOTYPE         The socket type is not supported by the protocol.
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114       The socketpair() function may fail if:
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116       EACCES     The process does not have appropriate privileges.
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119       ENOBUFS    Insufficient  resources were available in the system to per‐
120                  form the operation.
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123       ENOMEM     Insufficient memory was available to fulfill the request.
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126       ENOSR      There were insufficient STREAMS resources available for  the
127                  operation to complete.
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ATTRIBUTES

131       See attributes(5) for descriptions of the following attributes:
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136       ┌─────────────────────────────┬─────────────────────────────┐
137       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
138       ├─────────────────────────────┼─────────────────────────────┤
139       │Interface Stability          │Standard                     │
140       ├─────────────────────────────┼─────────────────────────────┤
141       │MT-Level                     │MT-Safe                      │
142       └─────────────────────────────┴─────────────────────────────┘
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