Carriage return and process-send-string

Carriage return and process-send-string

[Vibhav Pant]

While working on a library for the Language Server Protocol[1] (which
uses \r\n to
separate headers), I found out that `process-send-string` will convert
carriage returns in
the provided string to newlines. As an example, strace shows that

(process-send-string proc
    (format "Content-Length: 0\r\n\r\n")

ends up sending

read(0, "Content-Length: 0\n", 8192)  = 17
read(0, "\n", 8192)                     = 1
read(0, "\n", 8192)                     = 1
read(0, "\n", 8192)                     = 1

to the process. I tried setting `:coding-system` in `make-process` to
`'no-conversion`, but
this didn't fix the issue. Is this intended behavior? If so, are there
any ways to go around it?

Thanks,
Vibhav

[1] Language Server Protocol:
https://github.com/Microsoft/language-server-protocol

-- 
Vibhav Pant
vibhavp@gmail.com

Re: Carriage return and process-send-string

[Helmut Eller]

On Thu, Dec 08 2016, Vibhav Pant wrote:

> (process-send-string proc
>     (format "Content-Length: 0\r\n\r\n")
>
> ends up sending
>
> read(0, "Content-Length: 0\n", 8192)  = 17

That's the receiving side, not the sender.

Are you using a subprocess or a socket?  A subprocess can go through a
PTY which can do all sorts of translations on the receiving side.

Helmut