SYNOPSIS
#include <nng/transport/tcp/tcp.h>
int nng_tcp_register(void);DESCRIPTION
The tcp transport provides communication support between nng sockets across a TCP/IP network. Both IPv4 and IPv6 are supported when the underlying platform also supports it.
Registration
The nng_tcp transport is generally built-in to the nng core, so no extra steps to use it should be necessary.
URI Format
This transport uses URIs using the scheme tcp://, followed by
an IP address or hostname, followed by a colon and finally a
TCP port number.
For example, to contact port 80 on the localhost either of the following URIs
could be used: tcp://127.0.0.1:80 or tcp://localhost:80.
When specifying IPv6 addresses, the address must be enclosed in
square brackets ([]) to avoid confusion with the final colon
separating the port.
For example, the same port 80 on the IPv6 loopback address (::1) would
be specified as tcp://[::1]:80.
| When using symbolic names, the name is resolved when the name is first used. nng won’t become aware of changes in the name resolution until restart, usually. (This is a bug and will likely be fixed in the future.) |
The special value of 0 (INADDR_ANY)
can be used for a listener to indicate that it should listen on all
interfaces on the host.
A short-hand for this form is to either omit the address, or specify
the asterisk (*) character.
For example, the following three URIs are all equivalent,
and could be used to listen to port 9999 on the host:
-
tcp://0.0.0.0:9999 -
tcp://*:9999 -
tcp://:9999
The entire URI must be less than NNG_MAXADDRLEN bytes long.
Socket Address
When using an nng_sockaddr structure,
the actual structure is either of type
nng_sockaddr_in (for IPv4) or
nng_sockaddr_in6 (for IPv6).
Transport Options
The nng_tcp transport has no special options.
| Options for TCP keepalive, linger, and nodelay are planned. |