libwebsockets/minimal-examples-lowlevel/ws-client/minimal-ws-client/README.md
2021-11-02 07:12:47 +00:00

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# lws minimal ws client
This connects to libwebsockets.org using the dumb-increment-protocol.
It demonstrates how to use the connection retry and backoff stuff in lws.
## build
```
$ cmake . && make
```
## Commandline Options
Option|Meaning
---|---
-d|Set logging verbosity
-s|Use a specific server instead of libwebsockets.org, eg `--server localhost`. Implies LCCSCF_ALLOW_SELFSIGNED
-p|Use a specific port instead of 443, eg `--port 7681`
-j|Allow selfsigned tls cert
-k|Allow insecure certs
-m|Skip server hostname check
-n|Skip tls usage
-e|Allow expired certs
--protocol|Use a specific ws subprotocol rather than dumb-increment-protocol, eg, `--protocol myprotocol`
## usage
Just run it, it will connect to libwebsockets.org and spew incrementing numbers
sent by the server at 20Hz
```
$ ./lws-minimal-ws-client
[2020/01/22 05:38:47:3409] U: LWS minimal ws client
[2020/01/22 05:38:47:4456] N: Loading client CA for verification ./libwebsockets.org.cer
[2020/01/22 05:38:48:1649] U: callback_minimal: established
[2020/01/22 05:38:48:1739] N:
[2020/01/22 05:38:48:1763] N: 0000: 30 0
[2020/01/22 05:38:48:1765] N:
...
```
To test against the lws test server instead of libwebsockets.org, run the test
server as
```
$ libwebsockets-test-server -s
```
and run this test app with
```
$ ./lws-minimal-ws-client -s localhost -p 7681 -j
```
You can kill and restart the server to confirm the client connection is re-
established if done within the backoff period.