The parameter s is a socket. If it is of type SOCK_DGRAMS, 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_STREAMS, 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. Generally, stream sockets may successfully 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.

connect() returns:

0

on success.

-1

on failure and sets errno to indicate the error.

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 family cannot be used with this socket.

EALREADY

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

EBADF

s is not a valid descriptor.

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 name parameter specifies an area outside the process address space.

EINPROGRESS

The socket is non-blocking and the connection cannot be completed immediately. It is possible to select(2) for completion by selecting the socket for writing.

EINTR

The connection attempt was interrupted before any data arrived by the delivery of a signal.

EINVAL

namelen is not the size of a valid address for the specified address family.

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 component of the path prefix of the path name in name.

ELOOP

Too many symbolic links were encountered in translating the path name in name.

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}. 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 name does not exist. The socket referred to by the path name in name does not exist.

ENOTDIR

A component of the path prefix of the path name in name is not a directory.

ENOTSOCK

The file referred to by name is not a socket.

EPROTOTYPE

The file referred to by name is a socket of a type other than the type of s (e.g., s is a SOCK_DGRAM socket, while name refers to a SOCK_STREAM socket).