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socket(2)
NAME
  socket - Create an end point for communication and return a descriptor

SYNOPSIS
  #include <sys/socket.h>

  int socket(
	  int domain,
	  int type,
	  int protocol );

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  socket(): XNS4.0, XNS5.0

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  domain
      Specifies the communications domain in which a socket is to be created.
      The domain argument specifies the address family with which addresses
      specified in later socket operations should be interpreted. The
      sys/socket.h file contains the definitions of the address families.
      Commonly used families are:

      AF_UNIX
	  UNIX pathnames

      AF_INET
	  Internet addresses (IPv4)

      AF_INET6
	  [Tru64 UNIX]	 Internet addresses (IPv6)

  type
      Specifies the semantics of communication. The sys/socket.h file defines
      the socket types. The following types are supported:

      SOCK_STREAM
	  Provides sequenced, reliable, two-way byte streams with a
	  transmission mechanism for out-of-band data.

      SOCK_DGRAM
	  Provides datagrams, which are connectionless messages of a fixed
	  maximum length.

      SOCK_RAW
	  [Tru64 UNIX]	 Provides access to internal network protocols and
	  interfaces. This type of socket is available only to a process with
	  the superuser privilege.

  protocol
      Specifies a particular protocol to be used with the socket. Specifying
      a protocol of 0 (zero) causes the socket() function to default to the
      typical protocol for the requested type of returned socket.

DESCRIPTION
  The socket() function creates a socket of the specified type in the
  specified domain.

  The socket() function returns a descriptor (an integer) that can be used in
  later system calls that operate on sockets.

  Socket level options control socket operations. The getsockopt() and
  setsockopt() functions are used to get and set these options, which are
  defined in the sys/socket.h file.

  The sensitivity level of the new socket is inherited from the creating
  process. The information label of the new socket is set to System Low.

RETURN VALUES
  Upon successful completion, the socket() function returns a nonnegative
  integer (the socket descriptor). Otherwise, a value of -1 is returned and
  errno is set to indicate the error.

ERRORS
  If the socket() function fails, errno may be set to one of the following
  values:

  [EACCES]
      The process have not have appropriate privileges.

  [EAFNOSUPPORT]
      The addresses in the specified address family are not supported.

  [EMFILE]
      The per-process descriptor table is full.

  [ENFILE]
      No more file descriptors are available for the system.

  [ENOBUFS]
      Insufficient resources were available in the system to complete the
      call.

  [ENOMEM]
      The system was unable to allocate kernel memory to increase the process
      descriptor table.

  [ENOSR]
      The available STREAMS resources were insufficient for the operation to
      complete.

  [EPERM]
      [Tru64 UNIX]  The process is attempting to open a raw socket and does
      not have the superuser privilege.

  [EPROTONOSUPPORT]
      The protocol is not supported by the specified address family or the
      protocol is not supported.

  [EPROTOTYPE]
      The socket type is not supported by the protocol.

SEE ALSO
  Functions: accept(2), bind(2), connect(2), listen(2), getsockname(2),
  getsockopt(2), recv(2), recvfrom(2), recvmsg(2), send(2), sendto(2),
  sendmsg(2), setsockopt(2), shutdown(2), socketpair(2)

  Standards: standards(5)

  Network Programmer's Guide

Index for Section 2

Alphabetical listing for S

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