在Golang中，为什么conn.Write tcp响应为空？

Question

I have a tcp server that reads a file that sends the file content to the client.

The 'status.txt' file contains only a boolean.

When I curl, this shows true (with leading space).

dat, err := ioutil.ReadFile("./status.txt")
conn.Write([]byte(" " + string(dat)))

Whereas this code results in curl: (52) Empty reply from server.

conn.Write([]byte(string(dat)))

Any clue why this happens? I don't want to have to pad my response string.

Answer 1

Don't use Curl if you are not using HTTP protocol. Curl is expecting certain format of the message that is compatible with HTTP protocol. If you send text "true", that is for sure not valid HTTP Header.

To test TCP server use Netcat instead:

nc localhost port