关于data, err, partial = tcpsock:receive(pattern?)中，err=closed的问题

[小镇错题家]

我的代码逻辑是这样，需要从body中提取每一行数据，但是无法判断数据是否以及接收完毕。最后一次接收时err=closed，这可以表示数据接收完毕了吗？关于err=closed有文档定义吗，其他err错误还有什么呢？官网上没有查到相关资料，恳请回复

```

content_by_lua_block {
             local socket, err = ngx.req.socket()
             local ret = ''
             while true do
                local buf, err_msg, partial = socket:receive('*l')
                ngx.log(ngx.ERR, buf)
                ngx.log(ngx.ERR, err_msg)
                if err_msg then
                     break
                end
                ret = ret .. buf
             end
             ngx.say(ret)
         }

```

日志

```

2023/06/06 11:21:19 [error] 18724#0: *55 [lua] content_by_lua(nginx.conf:44):6: hello, client: 172.19.124.56, server: , request: "POST /t HTTP/1.1", host: "172.18.2.33:8081"
2023/06/06 11:21:19 [error] 18724#0: *55 [lua] content_by_lua(nginx.conf:44):7: nil, client: 172.19.124.56, server: , request: "POST /t HTTP/1.1", host: "172.18.2.33:8081"
2023/06/06 11:21:19 [error] 18724#0: *55 [lua] content_by_lua(nginx.conf:44):6:  world, client: 172.19.124.56, server: , request: "POST /t HTTP/1.1", host: "172.18.2.33:8081"
2023/06/06 11:21:19 [error] 18724#0: *55 [lua] content_by_lua(nginx.conf:44):7: nil, client: 172.19.124.56, server: , request: "POST /t HTTP/1.1", host: "172.18.2.33:8081"
2023/06/06 11:21:19 [error] 18724#0: *55 [lua] content_by_lua(nginx.conf:44):6: nil, client: 172.19.124.56, server: , request: "POST /t HTTP/1.1", host: "172.18.2.33:8081"
2023/06/06 11:21:19 [error] 18724#0: *55 [lua] content_by_lua(nginx.conf:44):7: closed, client: 172.19.124.56, server: , request: "POST /t HTTP/1.1", host: "172.18.2.33:8081"

```

[xue]

In case of success, it returns the data received; in case of error, it returns nil with a string describing the error and the partial data received so far.