1.\" Copyright (c) 1983, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)connect.2 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/sys/connect.2,v 1.11.2.8 2003/04/05 16:59:01 ceri Exp $ 34.\" $DragonFly: src/lib/libc/sys/connect.2,v 1.2 2003/06/17 04:26:47 dillon Exp $ 35.\" 36.Dd June 4, 1993 37.Dt CONNECT 2 38.Os 39.Sh NAME 40.Nm connect 41.Nd initiate a connection on a socket 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In sys/types.h 46.In sys/socket.h 47.Ft int 48.Fn connect "int s" "const struct sockaddr *name" "socklen_t namelen" 49.Sh DESCRIPTION 50The parameter 51.Fa s 52is a socket. 53If it is of type 54.Dv SOCK_DGRAM , 55this call specifies the peer with which the socket is to be associated; 56this address is that to which datagrams are to be sent, 57and the only address from which datagrams are to be received. 58If the socket is of type 59.Dv SOCK_STREAM , 60this call attempts to make a connection to 61another socket. 62The other socket is specified by 63.Fa name , 64which is an address in the communications space of the socket. 65Each communications space interprets the 66.Fa name 67parameter in its own way. 68Generally, stream sockets may successfully 69.Fn connect 70only once; datagram sockets may use 71.Fn connect 72multiple times to change their association. 73Datagram sockets may dissolve the association 74by connecting to an invalid address, such as a null address. 75.Sh RETURN VALUES 76.Rv -std connect 77.Sh ERRORS 78The 79.Fn connect 80call fails if: 81.Bl -tag -width Er 82.It Bq Er EBADF 83.Fa s 84is not a valid descriptor. 85.It Bq Er ENOTSOCK 86.Fa s 87is a descriptor for a file, not a socket. 88.It Bq Er EADDRNOTAVAIL 89The specified address is not available on this machine. 90.It Bq Er EAFNOSUPPORT 91Addresses in the specified address family cannot be used with this socket. 92.It Bq Er EISCONN 93The socket is already connected. 94.It Bq Er ETIMEDOUT 95Connection establishment timed out without establishing a connection. 96.It Bq Er ECONNREFUSED 97The attempt to connect was forcefully rejected. 98.It Bq Er ENETUNREACH 99The network is not reachable from this host. 100.It Bq Er EHOSTUNREACH 101The remote host is not reachable from this host. 102.It Bq Er EADDRINUSE 103The address is already in use. 104.It Bq Er EFAULT 105The 106.Fa name 107parameter specifies an area outside 108the process address space. 109.It Bq Er EINPROGRESS 110The socket is non-blocking 111and the connection cannot 112be completed immediately. 113It is possible to 114.Xr select 2 115for completion by selecting the socket for writing. 116.It Bq Er EALREADY 117The socket is non-blocking 118and a previous connection attempt 119has not yet been completed. 120.El 121.Pp 122The following errors are specific to connecting names in the UNIX domain. 123These errors may not apply in future versions of the UNIX IPC domain. 124.Bl -tag -width Er 125.It Bq Er ENOTDIR 126A component of the path prefix is not a directory. 127.It Bq Er ENAMETOOLONG 128A component of a pathname exceeded 255 characters, 129or an entire path name exceeded 1023 characters. 130.It Bq Er ENOENT 131The named socket does not exist. 132.It Bq Er EACCES 133Search permission is denied for a component of the path prefix. 134.It Bq Er EACCES 135Write access to the named socket is denied. 136.It Bq Er ELOOP 137Too many symbolic links were encountered in translating the pathname. 138.El 139.Sh SEE ALSO 140.Xr accept 2 , 141.Xr getpeername 2 , 142.Xr getsockname 2 , 143.Xr select 2 , 144.Xr socket 2 145.Sh HISTORY 146The 147.Fn connect 148function call appeared in 149.Bx 4.2 . 150