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CONNECT(2)                  BSD System Calls Manual                 CONNECT(2)

     connect - initiate a connection on a socket

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

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

     The parameter s is a socket.  If it is of type 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
     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 commu-
     nications space of the socket.  Each communications space interprets the
     name parameter in its own way.  Generally, stream sockets may success-
     fully connect() only once; datagram sockets may use connect() multiple
     times to change their association.  Datagram sockets may dissolve the
     association by connecting to an invalid address, such as a null address.

     If the connection or binding succeeds, 0 is returned.  Otherwise a -1 is
     returned, and a more specific error code is stored in errno.

     The connect() call fails if:

     [EBADF]            S is not a valid descriptor.

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

     [EADDRNOTAVAIL]    The specified address is not available on this

     [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.

     [EINVAL]           A TCP connection with a local broadcast, the all-ones
                        or a multicast address as the peer was attempted.

     [ECONNREFUSED]     The attempt to connect was forcefully rejected.

     [EINTR]            A connect was interrupted before it succeeded by the
                        delivery of a signal.

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

     [EADDRINUSE]       The address is already in use.

     [EFAULT]           The name parameter specifies an area outside the pro-
                        cess address space.

     [EINPROGRESS]      The socket is non-blocking and the connection cannot
                        be completed immediately.  It is possible to select(2)
                        or poll(2) for completion by selecting the socket for
                        writing, and also use getsockopt(2) with SO_ERROR to
                        check for error conditions.

     [EALREADY]         The socket is non-blocking and a previous connection
                        attempt has not yet been completed.

     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 {NAME_MAX} charac-
                        ters, or an entire path name exceeded {PATH_MAX} char-

     [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.

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

     The connect() function call appeared in 4.2BSD.

BSD                            February 15, 1999                           BSD