Unix domain sockets (sockets with address family AF_UNIX) are
represented as a (socket) file in the file system. They can only be used
to connect processes on the same host. The main advantage of AF_UNIX
sockets is that name conflicts are much easier to manage than port
conflicts and that access is determined by the file system permission
rules.
- unix_domain_socket(-Socket)
- Creates an AF_UNIX-domain stream-socket and unifies an identifier to it
with Socket. This predicate does not exist if the OS does not
support the AF_UNIX address family (e.g. MS-Windows).
Unix domain socket affect tcp_connect/2
(for clients) and tcp_bind/2
and
tcp_accept/3
(for servers). The address is an atom or string that is handled as a
file name. On most systems the length of this file name is limited to
128 bytes (including null terminator), but according to the Linux
documentation (unix(7)), portable applications must keep the address
below 92 bytes. Note that these lengths are in bytes. Non-ascii
characters may be represented as multiple bytes. If the length limit is
exceeded a representation_error(af_unix_name) exception is
raised.
