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CONNECT(2)		  FreeBSD System Calls Manual		    CONNECT(2)

     connect --	initiate a connection on a socket

     Standard C	Library	(libc, -lc)

     #include <sys/socket.h>

     connect(int s, const struct sockaddr *name, socklen_t namelen);

     The s argument is a socket.  If it	is of type SOCK_DGRAM, this call spec-
     ifies the peer with which the socket is to	be associated; this address is
     that to which datagrams are to be sent, and the only address from which
     datagrams are to be received.  If the socket is of	type SOCK_STREAM, this
     call attempts to make a connection	to another socket.  The	other socket
     is	specified by name, which is an address in the communications space of
     the socket.  namelen indicates the	amount of space	pointed	to by name, in
     bytes; the	sa_len member of name is ignored.  Each	communications space
     interprets	the name argument in its own way.  Generally, stream sockets
     may successfully connect()	only once; datagram sockets may	use connect()
     multiple times to change their association.  Datagram sockets may dis-
     solve the association by connecting to an invalid address,	such as	a null

     The connect() function returns the	value 0	if successful; otherwise the
     value -1 is returned and the global variable errno	is set to indicate the

     The connect() system call fails if:

     [EBADF]		The s argument is not a	valid descriptor.

     [EINVAL]		The namelen argument is	not a valid length for the ad-
			dress family.

     [ENOTSOCK]		The s argument is a descriptor for a file, not a

     [EADDRNOTAVAIL]	The specified address is not available on this ma-

     [EAFNOSUPPORT]	Addresses in the specified address family cannot be
			used with this socket.

     [EISCONN]		The socket is already connected.

     [ETIMEDOUT]	Connection establishment timed out without establish-
			ing a connection.

     [ECONNREFUSED]	The attempt to connect was forcefully rejected.

     [ECONNRESET]	The connection was reset by the	remote host.

     [ENETUNREACH]	The network is not reachable from this host.

     [EHOSTUNREACH]	The remote host	is not reachable from this host.

     [EADDRINUSE]	The address is already in use.

     [EFAULT]		The name argument specifies an area outside the
			process	address	space.

     [EINPROGRESS]	The socket is non-blocking and the connection cannot
			be completed immediately.  It is possible to select(2)
			for completion by selecting the	socket for writing.

     [EINTR]		The connection attempt was interrupted by the delivery
			of a signal.  The connection will be established in
			the background,	as in the case of EINPROGRESS.

     [EALREADY]		A previous connection attempt has not yet been com-

     [EACCES]		An attempt is made to connect to a broadcast address
			(obtained through the INADDR_BROADCAST constant	or the
			INADDR_NONE return value) through a socket that	does
			not provide broadcast functionality.

     [EAGAIN]		An auto-assigned port number was requested but no
			auto-assigned ports are	available.  Increasing the
			port range specified by	sysctl(3) MIB variables
			net.inet.ip.portrange.first and
			net.inet.ip.portrange.last may alleviate the problem.

     The following errors are specific to connecting names in the UNIX domain.
     These errors may not apply	in future versions of the UNIX IPC domain.

     [ENOTDIR]		A component of the path	prefix is not a	directory.

     [ENAMETOOLONG]	A component of a pathname exceeded 255 characters, or
			an entire path name exceeded 1023 characters.

     [ENOENT]		The named socket does not exist.

     [EACCES]		Search permission is denied for	a component of the
			path prefix.

     [EACCES]		Write access to	the named socket is denied.

     [ELOOP]		Too many symbolic links	were encountered in translat-
			ing the	pathname.

     [EPERM]		Write access to	the named socket is denied.

     accept(2),	getpeername(2),	getsockname(2),	select(2), socket(2),
     sysctl(3),	sysctl(8)

     The connect() system call appeared	in 4.2BSD.

FreeBSD	13.0			August 18, 2016			  FreeBSD 13.0


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