connect.2 revision 1.21 $NetBSD: connect.2,v 1.21 2003/01/18 11:33:02 thorpej Exp $
Copyright (c) 1983, 1993
The Regents of the University of California. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
must display the following acknowledgement:
This product includes software developed by the University of
California, Berkeley and its contributors.
4. Neither the name of the University nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
@(#)connect.2 8.1 (Berkeley) 6/4/93
.Dd October 16, 2001 .Dt CONNECT 2 .Os .Sh NAME .Nm connect .Nd initiate a connection on a socket .Sh LIBRARY .Lb libc .Sh SYNOPSIS .Fd #include \*[Lt]sys/socket.h\*[Gt] .Ft int .Fn connect "int s" "const struct sockaddr *name" "socklen_t namelen" .Sh DESCRIPTION The parameter .Fa s is a socket. If it is of type .Dv SOCK_DGRAM , this call specifies 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 .Dv SOCK_STREAM , this call attempts to make a connection to another socket. The other socket is specified by .Fa name , which is an address in the communications space of the socket. Each communications space interprets the .Fa name parameter in its own way. Generally, stream sockets may successfully .Fn connect only once; datagram sockets may use .Fn connect multiple times to change their association. Datagram sockets may dissolve the association by connecting to an invalid address, such as a null address. .Sh RETURN VALUES If the connection or binding succeeds, 0 is returned. Otherwise a -1 is returned, and a more specific error code is stored in .Va errno . .Sh ERRORS The .Fn connect call fails if: l -tag -width Er t Bq Er EBADF .Fa s is not a valid descriptor. t Bq Er ENOTSOCK .Fa s is a descriptor for a file, not a socket. t Bq Er EADDRNOTAVAIL The specified address is not available on this machine. t Bq Er EAFNOSUPPORT Addresses in the specified address family cannot be used with this socket. t Bq Er EISCONN The socket is already connected. t Bq Er ETIMEDOUT Connection establishment timed out without establishing a connection. t Bq Er ECONNREFUSED The attempt to connect was forcefully rejected. t Bq Er ENETUNREACH The network isn't reachable from this host. t Bq Er EADDRINUSE The address is already in use. t Bq Er EFAULT The .Fa name parameter specifies an area outside the process address space. t Bq Er EINPROGRESS The socket is non-blocking and the connection cannot be completed immediately. It is possible to .Xr select 2 or .Xr poll 2 for completion by selecting or polling the socket for writing. The success or failure of the connect operation may be determined by using .Xr getsockopt 2 to read the socket error status with the .Dv SO_ERROR option at the .Dv SOL_SOCKET level. The returned socket error status is zero on success, or one of the error codes listed here on failure. t Bq Er EALREADY The socket is non-blocking and a previous connection attempt has not yet been completed. .El
Copyright (c) 1983, 1993
The Regents of the University of California. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
must display the following acknowledgement:
This product includes software developed by the University of
California, Berkeley and its contributors.
4. Neither the name of the University nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
@(#)connect.2 8.1 (Berkeley) 6/4/93
.Dd October 16, 2001 .Dt CONNECT 2 .Os .Sh NAME .Nm connect .Nd initiate a connection on a socket .Sh LIBRARY .Lb libc .Sh SYNOPSIS .Fd #include \*[Lt]sys/socket.h\*[Gt] .Ft int .Fn connect "int s" "const struct sockaddr *name" "socklen_t namelen" .Sh DESCRIPTION The parameter .Fa s is a socket. If it is of type .Dv SOCK_DGRAM , this call specifies 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 .Dv SOCK_STREAM , this call attempts to make a connection to another socket. The other socket is specified by .Fa name , which is an address in the communications space of the socket. Each communications space interprets the .Fa name parameter in its own way. Generally, stream sockets may successfully .Fn connect only once; datagram sockets may use .Fn connect multiple times to change their association. Datagram sockets may dissolve the association by connecting to an invalid address, such as a null address. .Sh RETURN VALUES If the connection or binding succeeds, 0 is returned. Otherwise a -1 is returned, and a more specific error code is stored in .Va errno . .Sh ERRORS The .Fn connect call fails if: l -tag -width Er t Bq Er EBADF .Fa s is not a valid descriptor. t Bq Er ENOTSOCK .Fa s is a descriptor for a file, not a socket. t Bq Er EADDRNOTAVAIL The specified address is not available on this machine. t Bq Er EAFNOSUPPORT Addresses in the specified address family cannot be used with this socket. t Bq Er EISCONN The socket is already connected. t Bq Er ETIMEDOUT Connection establishment timed out without establishing a connection. t Bq Er ECONNREFUSED The attempt to connect was forcefully rejected. t Bq Er ENETUNREACH The network isn't reachable from this host. t Bq Er EADDRINUSE The address is already in use. t Bq Er EFAULT The .Fa name parameter specifies an area outside the process address space. t Bq Er EINPROGRESS The socket is non-blocking and the connection cannot be completed immediately. It is possible to .Xr select 2 or .Xr poll 2 for completion by selecting or polling the socket for writing. The success or failure of the connect operation may be determined by using .Xr getsockopt 2 to read the socket error status with the .Dv SO_ERROR option at the .Dv SOL_SOCKET level. The returned socket error status is zero on success, or one of the error codes listed here on failure. t Bq Er EALREADY The socket is non-blocking and a previous connection attempt has not yet been completed. .El
p The following errors are specific to connecting names in the x domain. These errors may not apply in future versions of the x IPC domain. l -tag -width Er t Bq Er ENOTDIR A component of the path prefix is not a directory. t Bq Er ENAMETOOLONG A component of a pathname exceeded .Dv {NAME_MAX} characters, or an entire path name exceeded .Dv {PATH_MAX} characters. t Bq Er ENOENT The named socket does not exist. t Bq Er EACCES Search permission is denied for a component of the path prefix, or write access to the named socket is denied. t Bq Er ELOOP Too many symbolic links were encountered in translating the pathname. .El .Sh SEE ALSO .Xr accept 2 , .Xr getsockname 2 , .Xr getsockopt 2 , .Xr poll 2 , .Xr select 2 , .Xr socket 2 .Sh HISTORY The .Fn connect function call appeared in x 4.2 .
Indexes created Mon Oct 13 16:09:52 GMT 2025