How do I redirect output from a process to another buffer?
reddit / emacs

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cuntymccuntlicker · 2022-07-04 01:38

I have a python interpreter running in one buffer, I want to send it
some command, and have the output be placed into a different buffer,
say "buf-out". For instance, if I sent

​

    import time
    for i in range(10):
        time.sleep(0.5)
        print(i, end="\r")

to my python interpreter, I would like to see in "buf-out" the
sequence of numbers from 0 to 9 overwrite each other every half-
second. Essentially, I want to see in "buf-out" exactly what I would
see in the shell after pressing RET. Is there a way to do this? I
tried with comint-redirect but it does not interpret the carriage
return, and it also displays the ">>>" prompt that gets printed after
the code finishes running.

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cuntymccuntlicker · 2022-07-04 04:29

Is there any way to modify comint-output-filter or something?

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ieure · 2022-07-04 16:08

(setq comint-redirect-output-buffer "*destination buffer*")
    (add-hook comint-preoutput-filter-functions #'comint-redirect-
preoutput-filter)

This is probably going to see everything that gets written, including
the REPL prompt, so you may need to build your own function using
`comint-redirect-preoutput-filter` and the `python-mode` stuff.

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1nc0ns1st3nt · 2022-07-05 09:10

I would also recommend **alternatively** using `ob-python`, which is
using source blocks in an org file, it is a style of literate
programming, and the output will be saved in the same buffer, however,
to  redirect to another buffer, here are some tweaks that you can
apply: [https://emacs.stackexchange.com/questions/23870/org-babel-
result-to-a-separate-
buffer](https://emacs.stackexchange.com/questions/23870/org-babel-
result-to-a-separate-buffer)