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socket(2)
NAME
  socket - Creates an end point for communication and returns 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(): XPG4-UNIX

  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   ARPA Internet addresses

  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  [Digital] Provides access to internal network protocols
		      and interfaces. This type of socket is available only
		      to a process with 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.

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 available
	    in the kernel.

  [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.

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

  [EPROTONOSUPPORT]
	    The socket in the specified address family is not supported.

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

RELATED INFORMATION
  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)