Copyright (c) 1983 Regents of the University of California.
All rights reserved. The Berkeley software License Agreement
specifies the terms and conditions for redistribution.

@(#)connect.2 5.1 (Berkeley) 05/15/85

C 5 connect - initiate a connection on a socket

#include <sys/types.h>
#include <sys/socket.h>

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

The parameter s is a socket. If it is of type SOCK_DGRAM, then this call permanently specifies the peer to which datagrams are to be sent; if it is of type SOCK_STREAM, then 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. Each communications space interprets the name parameter in its own way. If the connection or binding succeeds, then 0 is returned. Otherwise a -1 is returned, and a more specific error code is stored in errno. The call fails if:

20 [EBADF] S is not a valid descriptor.

20 [ENOTSOCK] S is a descriptor for a file, not a socket.

20 [EADDRNOTAVAIL] The specified address is not available on this machine.

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

20 [EISCONN] The socket is already connected.

20 [ETIMEDOUT] Connection establishment timed out without establishing a connection.

20 [ECONNREFUSED] The attempt to connect was forcefully rejected.

20 [ENETUNREACH] The network isn't reachable from this host.

20 [EADDRINUSE] The address is already in use.

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

20 [EWOULDBLOCK] The socket is non-blocking and the and the connection cannot be completed immediately. It is possible to select (2) the socket while it is connecting by selecting it for writing.

accept(2), select(2), socket(2), getsockname(2)