CONNECT(2) SYSTEM CALLS CONNECT(2) NAME connect - initiate a connection on a socket SYNOPSIS #include #include int connect(s, name, namelen) int s; struct sockaddr *name; int namelen; DESCRIPTION The parameter _s is a socket. If it is of type SOCK_DGRAM, then 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 it is of type SOCK_STREAM, then this call attempts to make a connection to another socket. The other socket is specified by _n_a_m_e which is an address in the communications space of the socket. Each communications space interprets the _n_a_m_e parameter in its own way. Gen- erally, stream sockets may successfully connect() only once; datagram sockets may use connect() multiple times to change their association. Datagram sockets may dissolve the asso- ciation by connecting to an invalid address, such as a null address. RETURN VALUES connect() returns: 0 on success. -1 on failure and sets errno to indicate the error. ERRORS The call fails if: EADDRINUSE The address is already in use. EADDRNOTAVAIL The specified address is not available on the remote machine. EAFNOSUPPORT Addresses in the specified address fam- ily cannot be used with this socket. EALREADY The socket is non-blocking and a previ- ous connection attempt has not yet been completed. EBADF _s is not a valid descriptor. Sun Release 4.1 Last change: 21 January 1990 1 CONNECT(2) SYSTEM CALLS CONNECT(2) ECONNREFUSED The attempt to connect was forcefully rejected. The calling program should close(2V) the socket descriptor, and issue another socket(2) call to obtain a new descriptor before attempting another connect(2) call. EFAULT The _n_a_m_e parameter specifies an area outside the process address space. EINPROGRESS The socket is non-blocking and the con- nection cannot be completed immediately. It is possible to select(2) for comple- tion by selecting the socket for writ- ing. EINTR The connection attempt was interrupted before any data arrived by the delivery of a signal. EINVAL _n_a_m_e_l_e_n is not the size of a valid address for the specified address fam- ily. EISCONN The socket is already connected. ENETUNREACH The network is not reachable from this host. ENOTSOCK _s is a descriptor for a file, not a socket. ETIMEDOUT Connection establishment timed out without establishing a connection. 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. EACCES Search permission is denied for a com- ponent of the path prefix of the path name in _n_a_m_e. ELOOP Too many symbolic links were encountered in translating the path name in _n_a_m_e. EIO An I/O error occurred while reading from or writing to the file system. ENAMETOOLONG The length of the path argument exceeds {PATH_MAX}. Sun Release 4.1 Last change: 21 January 1990 2 CONNECT(2) SYSTEM CALLS CONNECT(2) A pathname component is longer than {NAME_MAX} (see sysconf(2V)) while {_POSIX_NO_TRUNC} is in effect (see pathconf(2V)). ENOENT A component of the path prefix of the path name in _n_a_m_e does not exist. The socket referred to by the path name in _n_a_m_e does not exist. ENOTDIR A component of the path prefix of the path name in _n_a_m_e is not a directory. ENOTSOCK The file referred to by _n_a_m_e is not a socket. EPROTOTYPE The file referred to by _n_a_m_e is a socket of a type other than the type of _s (e.g., _s is a SOCK_DGRAM socket, while _n_a_m_e refers to a SOCK_STREAM socket). SEE ALSO accept(2), close(2V), connect(2), getsockname(2), select(2), socket(2) Sun Release 4.1 Last change: 21 January 1990 3