Re: where does Emacs source the shell configuration files from?

[Eli Zaretskii]

> From: Sivaram Neelakantan <nsivaram.net@gmail.com>
> Date: Fri, 04 Oct 2024 18:40:15 +0530
> User-Mail-Address: nsivaram.net@gmail.com
> 
> on GNU Emacs 29.4 (build 2, x86_64-w64-mingw32) of 2024-07-05, when I
> invoke M-x shell, I get garbled characters which seem to go away with
> with setting PS1; see below
> 
> --8<---------------cut here---------------start------------->8---
> bash: cannot set terminal process group (-1): Inappropriate ioctl for device
> bash: no job control in this shell
> ]0;/c/gnu/emacs-29.4/bin
> agam@agamam  /c/gnu/emacs-29.4/bin
> $ echo $PS1
> \[\e]0;\w\a\]\n\[\e[32m\]\u@\h \[\e[35m\]$MSYSTEM\[\e[0m\] 
> \[\e[33m\]\w\[\e[0m\]\n\$
> ]0;/c/gnu/emacs-29.4/bin
> agam@agamam  /c/gnu/emacs-29.4/bin
> $ export PS1="\e[0;31m[\u@\h \W]\$ \e[m "
> [agam@agamam bin]$  pwd
> /c/gnu/emacs-29.4/bin
> [agam@agamam bin]$
> --8<---------------cut here---------------end--------------->8---
> 
> So, I try to plug in the above PS1 in different places and it doesn't to
> seem to get read at all.  I've tried ~/.bashrc   which points to
> c:/Users/agam/AppData/Roaming and ~/.emacs_bash in the same place. I've
> also tried .bashrc in mys home directory but it doesn't be seem be read
> 
> --8<---------------cut here---------------start------------->8---
> 
>     (setenv "BASH_ENV" "~/.bashrc")
>     (setq explicit-shell-file-name "C:/msys64/usr/bin/bash.exe") 
>     (setq shell-file-name          "C:/msys64/usr/bin/bash.exe")
>     (setenv "SHELL" shell-file-name)
>     (setq shell-command-switch "-ic")
>     (add-hook 'comint-output-filter-functions 'comint-strip-ctrl-m)
>     (autoload 'ansi-color-for-comint-mode-on "ansi-color" nil t)
>     (add-hook 'shell-mode-hook 'ansi-color-for-comint-mode-on)
> --8<---------------cut here---------------end--------------->8---
> 
> What am I doing incorrectly?  And where should the PS1 be plugged in?
> And is there a way to see which config files are being sourced when M-x
> shell is invoked?

The problem is that you are using the MSYS Bash, and that Windows
doesn't support the ioctl calls required for "M-x shell" to work with
Bash.

Emacs on Windows uses pipes to communicate with sub-processes, so any
Bash settings that are meant for interactive use will likely not work
in "M-x shell", because pipes are not terminal devices.

You could try customizing explicit-bash-args, maybe it will help.