CONNECT(2) CONNECT(2) NAME connect - initiate a connection on a socket SYNOPSIS #include #include 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 the socket 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. Generally, stream sock‐ ets may successfully _c_o_n_n_e_c_t only once; datagram sockets may use _c_o_n_‐ _n_e_c_t multiple times to change their association. Datagram sockets may dissolve the association by connecting to an invalid address, such as a null address. RETURN VALUE If the connection or binding succeeds, then 0 is returned. Otherwise a -1 is returned, and a more specific error code is stored in _e_r_r_n_o. ERRORS The 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 machine. [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 estab‐ lishing a connection. [ECONNREFUSED] The attempt to connect was forcefully rejected. [ENETUNREACH] The network isn’t reachable from this host. [EADDRINUSE] The address is already in use. [EFAULT] The _n_a_m_e parameter specifies an area outside the process address space. [EINPROGRESS] The socket is non-blocking and the connection can‐ not be completed immediately. It is possible to _s_e_l_e_c_t(2) for completion by selecting the socket for writing. [EALREADY] The socket is non-blocking and a previous connec‐ tion 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. [EINVAL] The pathname contains a character with the high-order bit set. [ENAMETOOLONG] A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters. [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 translating the pathname. SEE ALSO accept(2), select(2), socket(2), getsockname(2) 4.2 Berkeley Distribution May 22, 1986 CONNECT(2)