Question

Is there a way to execute emacs command on multiple buffers without having to selecting them individually and executing it on each individual buffer.

I usually open multiple files matching a particular regex, e.g. ~/*.py and wish to enable a particular mode, say hs-minor-mode or glasses-mode on each, or say execute C-c @ C-M-h on each. Currently I have to select each one of them and do it individually. So is there a hack or a loop to automate the task.

Lets say I mark the buffers from the buffer-list and then run the command for all those marked.

I tried this but after executing the commands in eval-expression I completely lost access to my minibuffer, meaning whenever I typed M-x the minibuffer returned this

unable to access the minibuffer emacs error “Process Menu Mode doesn’t support Hideshow Minor Mode”

and I was forced to actually kill the entire emacs process because the C-x C-s wasn’t working neither was the End Task.

PS: I have no experience in elisp

Answer 1

You can use ibuffer mode for this (It is part of the default Emacs distribution).

(global-set-key "\C-x\C-b" 'ibuffer) ;; make ibuffer the default

In *Ibuffer* you can mark the required buffers with m and then
execute a form in each with E.

Generally, ibuffer is a lot more flexible then the usual buffer list and I think ibuffer should really be the default buffer-list in Emacs.

If you do this often, you might want to switch those particular modes on every time you enter python mode by attaching them to the mode-hook:

(add-hook 'python-mode-hook 'hs-minor-mode)
(add-hook 'python-mode-hook 'glasses-mode)