How can I run Cygwin Bash Shell from within Emacs?

Question

I am running GNU Emacs on Windows so entering:

M-x shell 

launches the Windows command-line DOS shell. However, I would like to instead be able to run the Cygwin Bash Shell (or any other non-Windows shell) from within Emacs. How can this be easily done?

Answer 1

shell-file-name is the variable that controls which shell Emacs uses when it wants to run a shell command.

explicit-shell-file-name is the variable that controls which shell M-x shell starts up.

Ken's answer changes both of those, which you may or may not want.

You can also have a function that starts a different shell by temporarily changing explicit-shell-file-name:

(defun cygwin-shell ()   "Run cygwin bash in shell mode."   (interactive)   (let ((explicit-shell-file-name "C:/cygwin/bin/bash"))     (call-interactively 'shell))) 

You will probably also want to pass the --login argument to bash, because you're starting a new Cygwin session. You can do that by setting explicit-bash-args. (Note that M-x shell uses explicit-PROGRAM-args, where PROGRAM is the filename part of the shell's pathname. This is why you should not include the .exe when setting the shell.

Answer 2

The best solution I've found to this is the following:

;; When running in Windows, we want to use an alternate shell so we ;; can be more unixy. (setq shell-file-name "C:/MinGW/msys/1.0/bin/bash") (setq explicit-shell-file-name shell-file-name) (setenv "PATH"     (concat ".:/usr/local/bin:/mingw/bin:/bin:"         (replace-regexp-in-string " " "\\\\ "             (replace-regexp-in-string "\\\\" "/"                 (replace-regexp-in-string "\\([A-Za-z]\\):" "/\\1"                     (getenv "PATH")))))) 

The problem with passing "--login" as cjm suggests is your shell will always start in your home directory. But if you're editing a file and you hit "M-x shell", you want your shell in that file's directory. Furthermore, I've tested this setup with "M-x grep" and "M-x compile". I'm suspicious that other examples here wouldn't work with those due to directory and PATH problems.

This elisp snippet belongs in your ~/.emacs file. If you want to use Cygwin instead of MinGW, change the first string to C:/cygwin/bin/bash. The second string is prepended to your Windows PATH (after converting that PATH to an appropriately unixy form); in Cygwin you probably want "~/bin:/usr/local/bin:/usr/bin:" or something similar.