1.\" $NetBSD: connect.2,v 1.8 1995/10/12 15:40:48 jtc Exp $ 2.\" 3.\" Copyright (c) 1983, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)connect.2 8.1 (Berkeley) 6/4/93 35.\" 36.Dd June 4, 1993 37.Dt CONNECT 2 38.Os BSD 4.2 39.Sh NAME 40.Nm connect 41.Nd initiate a connection on a socket 42.Sh SYNOPSIS 43.Fd #include <sys/types.h> 44.Fd #include <sys/socket.h> 45.Ft int 46.Fn connect "int s" "const struct sockaddr *name" "int namelen" 47.Sh DESCRIPTION 48The parameter 49.Fa s 50is a socket. 51If it is of type 52.Dv SOCK_DGRAM , 53this call specifies the peer with which the socket is to be associated; 54this address is that to which datagrams are to be sent, 55and the only address from which datagrams are to be received. 56If the socket is of type 57.Dv SOCK_STREAM , 58this call attempts to make a connection to 59another socket. 60The other socket is specified by 61.Fa name , 62which is an address in the communications space of the socket. 63Each communications space interprets the 64.Fa name 65parameter in its own way. 66Generally, stream sockets may successfully 67.Fn connect 68only once; datagram sockets may use 69.Fn connect 70multiple times to change their association. 71Datagram sockets may dissolve the association 72by connecting to an invalid address, such as a null address. 73.Sh RETURN VALUES 74If the connection or binding succeeds, 0 is returned. 75Otherwise a -1 is returned, and a more specific error 76code is stored in 77.Va errno . 78.Sh ERRORS 79The 80.Fn connect 81call fails if: 82.Bl -tag -width Er 83.It Bq Er EBADF 84.Fa S 85is not a valid descriptor. 86.It Bq Er ENOTSOCK 87.Fa S 88is a descriptor for a file, not a socket. 89.It Bq Er EADDRNOTAVAIL 90The specified address is not available on this machine. 91.It Bq Er EAFNOSUPPORT 92Addresses in the specified address family cannot be used with this socket. 93.It Bq Er EISCONN 94The socket is already connected. 95.It Bq Er ETIMEDOUT 96Connection establishment timed out without establishing a connection. 97.It Bq Er ECONNREFUSED 98The attempt to connect was forcefully rejected. 99.It Bq Er ENETUNREACH 100The network isn't reachable from this host. 101.It Bq Er EADDRINUSE 102The address is already in use. 103.It Bq Er EFAULT 104The 105.Fa name 106parameter specifies an area outside 107the process address space. 108.It Bq Er EINPROGRESS 109The socket is non-blocking 110and the connection cannot 111be completed immediately. 112It is possible to 113.Xr select 2 114for completion by selecting the socket for writing. 115.It Bq Er EALREADY 116The socket is non-blocking 117and a previous connection attempt 118has not yet been completed. 119.El 120.Pp 121The following errors are specific to connecting names in the UNIX domain. 122These errors may not apply in future versions of the UNIX IPC domain. 123.Bl -tag -width Er 124.It Bq Er ENOTDIR 125A component of the path prefix is not a directory. 126.It Bq Er ENAMETOOLONG 127A component of a pathname exceeded 128.Dv {NAME_MAX} 129characters, or an entire path name exceeded 130.Dv {PATH_MAX} 131characters. 132.It Bq Er ENOENT 133The named socket does not exist. 134.It Bq Er EACCES 135Search permission is denied for a component of the path prefix. 136.It Bq Er EACCES 137Write access to the named socket is denied. 138.It Bq Er ELOOP 139Too many symbolic links were encountered in translating the pathname. 140.El 141.Sh SEE ALSO 142.Xr accept 2 , 143.Xr select 2 , 144.Xr socket 2 , 145.Xr getsockname 2 146.Sh HISTORY 147The 148.Fn connect 149function call appeared in 150.Bx 4.2 . 151