如何在bash中阅读websocket响应

Question

编写一个bash脚本以连接到gss:http://ws-feed.gdax.com 上的GDAX的Websocket Feed,但curl似乎不支持这个

curl "wss://ws-feed.gdax.com"
curl: (1) Protocol "wss" not supported or disabled in libcurl

Answer 1

假设你已node安装,我会wscat试一试; 它简单,直观,功能强大.否则,@ Pavel的答案有很多令人尊敬的websocket客户端替代方案.

# install
npm install -g wscat

# use
wscat -c "wss://ws-feed.gdax.com"

Answer 2

好吧,您可以尝试使用curl模拟所需的标头以获得一些响应:

• https://gist.github.com/htp/fbce19069187ec1cc486b594104f01d0或
• Linux Bash:如何打开websocket连接作为客户端

此外,还有其他与WebSocket服务器通信的方式,例如

• https://github.com/websockets/wscat
• https://github.com/bwasti/webpipe
• https://github.com/progrium/wssh

Answer 3

ws通过协议启动连接http，您必须更改ws为http一些额外的标头，如下所示：

curl --include \
     --no-buffer \
     --header "Connection: Upgrade" \
     --header "Upgrade: websocket" \
     --header "Host: example.com:80" \
     --header "Origin: http://example.com:80" \
     --header "Sec-WebSocket-Key: SGVsbG8sIHdvcmxkIQ==" \
     --header "Sec-WebSocket-Version: 13" \
     "https://ws-feed.gdax.com"

https://gist.github.com/htp/fbce19069187ec1cc486b594104f01d0

Answer 4

我想为此添加自己的工具：websocat。

有关服务的示例会话：

$ rlwrap  websocat wss://ws-feed.gdax.com

# Now enter this line (without the #) for the required JSON request:
# {"type":"subscribe","channels": [{ "name": "heartbeat", "product_ids": ["BTC-USD"] }]}

{"type":"subscriptions","channels":[{"name":"heartbeat","product_ids":["BTC-USD"]}]}
{"type":"heartbeat","last_trade_id":46274575,"product_id":"BTC-USD","sequence":6312079752,"time":"2018-07-12T22:32:42.655000Z"}
{"type":"heartbeat","last_trade_id":46274575,"product_id":"BTC-USD","sequence":6312079800,"time":"2018-07-12T22:32:43.656000Z"}
{"type":"heartbeat","last_trade_id":46274575,"product_id":"BTC-USD","sequence":6312079834,"time":"2018-07-12T22:32:44.656000Z"}
{"type":"heartbeat","last_trade_id":46274575,"product_id":"BTC-USD","sequence":6312079945,"time":"2018-07-12T22:32:45.656000Z"}
{"type":"heartbeat","last_trade_id":46274575,"product_id":"BTC-USD","sequence":6312079990,"time":"2018-07-12T22:32:46.657000Z"}
{"type":"heartbeat","last_trade_id":46274575,"product_id":"BTC-USD","sequence":6312080042,"time":"2018-07-12T22:32:47.657000Z"}
{"type":"heartbeat","last_trade_id":46274576,"product_id":"BTC-USD","sequence":6312080169,"time":"2018-07-12T22:32:48.657000Z"}

# To stop the feed, type this line: 
{"type":"unsubscribe","channels": [{ "name": "heartbeat", "product_ids": ["BTC-USD"] }]}
{"type":"subscriptions","channels":[]}

除了websocket客户端之外，websocat还支持WebSocket服务器和其他模式，并且通常旨在将websocket集成到“ UNIX”世界中。

Answer 5

考虑到这里有curl答案，虽然curl你可以建立连接但无法发送帧，我会添加我的。

我看到的答案curl是他们给了你一些命令，但没有解释。这就是我想填补的空白。

简而言之，websocket 协议是如何工作的？客户端连接到服务器，发送握手请求，接收“101 交换协议”（握手响应），然后来回发送帧。

握手看起来如下：

GET / HTTP/1.1
Host: ws.example.com
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: x3JJHMbDL1EzLkh9GBhXDw==
Sec-WebSocket-Version: 13
Origin: http://example.com

HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: HSmrc0sMlYUkAGmm5OPpG2HaGWk=

Upgrade使其从 HTTP(s) 切换到 websocket 协议。

Connection指定这Upgrade是一个逐跳标头（中介应该使用而不是转发的标头）。但我的实验表明它无需此标头即可工作。或者更准确地说，如果服务器前面有反向代理（例如nginx），则它可能是可选的。

Sec-WebSocket-Key/是此处、此处和此处Sec-WebSocket-Accept描述的安全措施。

Sec-WebSocket-Version指定 websocket 协议版本。根据 RFC 6455，它应该等于13。

Origin当客户端是浏览器并且请求页面的来源与 websocket 服务器 URL 的来源不匹配时需要。

有关构成 websocket 握手请求的详细说明，请参见此处。

HTTP/1.1 就是这样。HTTP/2 则是另一回事。

了解这一点可以与以下内容建立 websocket 连接curl：

$ curl -H 'Upgrade: websocket' \
       -H "Sec-WebSocket-Key: `openssl rand -base64 16`" \
       -H 'Sec-WebSocket-Version: 13' \
       --http1.1 \
       -sSv \
       https://ws.ifelse.io
...
> GET / HTTP/1.1
> Host: ws.ifelse.io
> Upgrade: websocket
> Sec-WebSocket-Key: e2dujvcbYbN747lapeH+WA==
> Sec-WebSocket-Version: 13
...
< HTTP/1.1 101 Switching Protocols
< Connection: upgrade
< upgrade: websocket
< sec-websocket-accept: 6wmMGMtN00aWw3loYd6P36EHKMI=

其他选项是wscat、websocat。