libtelnet-0.1.0.1: README.md
# Bindings to libtelnet
[](https://builds.sr.ht/~jack/libtelnet-haskell?)
This is a wrapper around
[libtelnet](https://github.com/seanmiddleditch/libtelnet), a C library
for handling Telnet streams, including option negotiation, &c. As a
cleartext protocol, Telnet is thorougly unsuitable for use on the open
internet, but you might have a niche where it makes sense:
* [MU*](https://en.wikipedia.org/wiki/MU*) games still use it, and so
the clients people want to use only speak Telnet,
* You might be speaking Telnet inside a
[stunnel](https://www.stunnel.org/), or
* You might have some ancient hardware that can't be updated, and
doesn't have ssh, but you want to talk to it using Haskell.
This library hews closely to the interface provided by the C
libtelnet, so reading the [excellent C
documentation](https://github.com/seanmiddleditch/libtelnet#ii-api)
will help you. The short version goes something like this:
1. Define an _event handler_ of type
`Network.Telnet.LibTelnet.EventHandler`. This function receives
callbacks that tell you what received data should be propagated to
the application, and what bytes need to be sent out over the
socket.
2. Pass your event handler (and some other flags) to
`Network.Telnet.LibTelnet.telnetInit`, which will give you access
to a `Telnet`, a garbage-collected _state tracker_.
3. Tell the state tracker that data has arrived on the socket, or that
you want to send data to the socket, by passing it to the library's
other functions.
## Other Resources
* A simple server example exists in
[`example/Main.hs`](https://git.sr.ht/~jack/libtelnet-haskell/tree/master/example/Main.hs).
* Questions should go to the
[libtelnet-haskell-discuss](https://lists.sr.ht/~jack/libtelnet-haskell-discuss)
mailing list.
* Bug reports should go to the
[bug tracker](https://todo.sr.ht/~jack/libtelnet-haskell).