On 5/1/21 8:09 AM, Eli Zaretskii wrote:
From: Thomas Hisch <thomas.hisch@ims.co.at>
Date: Sat, 1 May 2021 01:10:10 +0200
I would like that the configuration options of the three file
handles (stdin, stdout and stderr), when a new process is created
in emacs, are improved. What I'm specifically asking for is to
add support for individually specifying for each file-handle
whether it should be connected to a pty or not. Currently the
value of the process-connection-type variable applies to all
three file handles at once, which leads to a problem with the
following use-case:
Usually a program outputs ANSI escape sequences when its stdout
file-handle is connected to a pty. It is currently not possible to
communicate with a subprocess that is created by `start-file-process' by
writing to a pty (via stdin) and avoiding that this subprocess writes
ANSI escape sequences to stdout. This use-case is needed by magit, which
currently doesn't have support for displaying ANSI escape sequences but
it needs to communicate with it's started subprocesses via a PTY
(https://github.com/magit/magit/issues/3549).
We have make-pipe-process; can't you solve your problem by connecting
your process's stdout to such a pipe-process? If not, why not?
Thx Eli for the fast reply! I had to study the docs of make-pipe-process
and make-process to understand what you mean. However, I'm not fully
sure if I fully get what you mean.
AFAICS the pipe process which is returned by make-pipe-process can be
passed to the :stderr keyword argument of make-process. Is that what you
head in mind?
According to the docs of make-process, process-connection-type is
ignored if :stderr is passed to make-process:
This parameter and the value of ‘process-connection-type’ are
ignored if a non-‘nil’ value is specified for the ‘:stderr’ parameter;
in that case, the type will always be ‘pipe’.
What I want is that stdout and stderr are connected to a pipe but stdin
is connected to a pty.
Here is the new test script that I used
(let* (
(stderr-buffer (get-buffer-create "*stderr*"))
(stderr-proc (make-pipe-process :name "stderr"
:buffer stderr-buffer))
(process-buf (get-buffer-create "*temp*")))
(make-process
:name "isatty"
:buffer process-buf ;; it is not possible to pass the output of
make-pipe-process to :buffer
:connection-type 'pty ;; unfortunately ignored if :stderr is used
:stderr stderr-proc
:command (list "/tmp/output-isatty.py")))