The buffer-terminator package automatically kills buffers to help maintain a clean and efficient workspace, while also improving Emacs' performance by reducing the number of open buffers, thereby decreasing the number of active modes, timers, and other processes associated with those buffers.
Activating (buffer-terminator-mode) terminates all buffers that have been inactive for longer than the duration specified by buffer-terminator-inactivity-timeout (default: 30 minutes). It checks every buffer-terminator-interval (default: 10 minutes) to determine if a buffer should be terminated.
The following buffers are not terminated by default:
- Special buffers (These buffers are non-file buffers that: start with a space, or start and end with
*, or whose major mode is derived fromspecial-mode, or they serve as the Minibuffer). - Modified file-visiting buffers that have not been saved; the user must save them first.
- Buffers currently displayed in any visible window.
- Buffers associated with running processes.
(The default rules above are fully customizable. Users can define specific rules for keeping or terminating certain buffers by specifying a set of rules using buffer-terminator-rules-alist. These rules can include buffer name patterns or regular expressions, major-modes, buffer properties, etc.)
To install buffer-terminator from MELPA:
- If you haven't already done so, add MELPA repository to your Emacs configuration.
- Add the following code to the Emacs init file:
(use-package buffer-terminator
:ensure t
:custom
(buffer-terminator-verbose nil)
:config
(buffer-terminator-mode 1))Enable verbose mode to log buffer cleanup events:
(setq buffer-terminator-verbose t)Set the inactivity timeout (in seconds) after which buffers are considered inactive (default is 30 minutes):
(setq buffer-terminator-inactivity-timeout (* 30 60)) ; 30 minutesDefine how frequently the cleanup process should run (default is every 10 minutes):
(customize-set-variable 'buffer-terminator-interval (* 10 60)) ; 10 minutes(Using customize-set-variable allows buffer-terminator-interval to update the timer dynamically, without the need to restart buffer-terminator-mode.)
By default, buffer-terminator automatically determines which buffers are safe to terminate.
However, if you need to define specific rules for keeping or terminating certain buffers, you can configure them using buffer-terminator-rules-alist.
The buffer-terminator-rules-alist variable holds instructions for keeping or terminating buffers based on their names or regular expressions. Each rule is a cons cell where the key is a symbol indicating the rule type, and the value is either string or a list of strings.
Here is an example:
(setq buffer-terminator-rules-alist
'((kill-buffer-name . ("temporary-buffer-name1"
"temporary-buffer-name2"))
(keep-buffer-name . ("important-buffer-name1"
"important-buffer-name2"))
(kill-buffer-name . "temporary-buffer-name3")
(keep-buffer-name-regexp . ("\\` \\*Minibuf-[0-9]+\\*\\'"))
(kill-buffer-name-regexp . "compile-angel")
;; Retain special buffers (DO NOT REMOVE).
;;
;; (If you choose to kill special buffers by removing the following,
;; ensure that the special buffers you want to keep are added
;; keep-buffer-name or keep-buffer-name-regexp rules above.)
;;
;; DO NOT REMOVE special buffers unless you know of what you are doing.
(keep-buffer-property . special)
;; Retain process buffers.
;;
;; (Process buffers are buffers where an active process is running.
;; Removing the following will result in the termination of such
;; buffers, potentially disrupting active processes like vterm.)
(keep-buffer-property . process)
;; Retain visible buffers (DO NOT REMOVE).
;;
;; Visible buffer are those currently displayed in any window.
;; It is generally discouraged to set this to nil, as doing so may result
;; in the termination of visible buffers, except for the currently active
;; buffer in the selected window.
;;
;; DO NOT REMOVE visible buffers unless necessary.
(keep-buffer-property . visible)
;; Kill inactive buffers.
;; (This can be customized with `buffer-terminator-inactivity-timeout'
;; and `buffer-terminator-interval'.)
(kill-buffer-property . inactive)
;; Call a function that decides the fate of a buffer. It returns:
;; :kill Indicates that the buffer should be killed.
;; :keep Indicates that the buffer should be kept.
;; nil Leave decision to the next rule specified
;; in `buffer-terminator-rules-alist`.
;; (call-function . function-name)
;; Keep the remaining buffers that were not retained by previous rules
(return . :keep)))Here is another example by gavv, one of the first buffer-terminator users.
- Some users prefer terminating inactive buffers to improve Emacs' performance by reducing the number of open buffers. This, in turn, decreases the load from active modes, timers, and other processes associated with those buffers. Buffer-local modes and their timers consume both CPU and memory. Why keep them alive when they can be safely removed?
- Some users prefer to keep only the buffers they actively need open, helping to declutter the buffer list. Decluttering the buffer list can also improve the performance of other packages. For example, saving and loading an easysession or desktop.el is much faster when the buffer list is reduced.
- Some users prefer that buffers not part of an active window be automatically closed, as they are not actively needed.
- Some Emacs packages continue interacting with open buffers, even when they are buried (Reddit post: A function to periodically wipe buffers not recently shown; thoughts?).
Midnight-mode does not address the problem that buffer-terminator solves, which is the safe and frequent termination of inactive buffers.
Midnight mode and clean-buffer-list are for killing buffers once a day. The Midnight option clean-buffer-list-delay-general specifies the number of days before a buffer becomes eligible for auto-killing, rather than using seconds or minutes as a timeout.
In contrast, buffer-terminator allows specifying the timeout interval in seconds (Default: 30 minutes), enabling more frequent termination of inactive buffers.
The buffer-terminator package offers additional features that are not supported by midnight and clean-buffer-list, including:
- The buffer-terminator package is more customizable than Midnight Mode. It allows users to specify a customized list of rules using
buffer-terminator-rules-alist, enabling them to determine which buffers should be killed based on factors such as inactivity, visibility, buffer name, whether it's a file or process buffer, and other conditions. - Buffer-terminator does not kill visible buffers in other tabs, even if they exceed the timeout. This prevents disruptions to editing workflows. Buffer-terminator provides the option to choose whether to keep or kill specific types of buffers, such as those associated with processes or file-visiting buffers.
- Buffer-terminator avoids relying on
buffer-display-time, which is not always updated reliably. For instance,buffer-display-timemay not reflect activity when switching to a window or tab displaying a specific buffer. - Buffer-terminator does not kill special buffers by default, whereas Midnight kills all special buffers by default unless the user tells Midnight to ignore them. Midnight's behavior can disrupt packages like Corfu, Cape, Consult, Eglot, Flymake, and others that rely on special buffers to store data.
- Buffer-terminator can also kill specific special buffers. It is useful, for example, if the user want to keep special buffers (i.e. using buffer-terminator-keep-special-buffers), but with a few exceptions: The user still want to kill Help and helpful ... buffers (and maybe some other buffers related to documentation) if they weren't used for a while.
The buffer-terminator Emacs package has been written by James Cherti and is distributed under terms of the GNU General Public License version 3, or, at your choice, any later version.
Copyright (C) 2024 James Cherti
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program.
Other Emacs packages by the same author:
- minimal-emacs.d: This repository hosts a minimal Emacs configuration designed to serve as a foundation for your vanilla Emacs setup and provide a solid base for an enhanced Emacs experience.
- compile-angel.el: Speed up Emacs! This package guarantees that all .el files are both byte-compiled and native-compiled, which significantly speeds up Emacs.
- outline-indent.el: An Emacs package that provides a minor mode that enables code folding and outlining based on indentation levels for various indentation-based text files, such as YAML, Python, and other indented text files.
- easysession.el: Easysession is lightweight Emacs session manager that can persist and restore file editing buffers, indirect buffers/clones, Dired buffers, the tab-bar, and the Emacs frames (with or without the Emacs frames size, width, and height).
- vim-tab-bar.el: Make the Emacs tab-bar Look Like Vim’s Tab Bar.
- elispcomp: A command line tool that allows compiling Elisp code directly from the terminal or from a shell script. It facilitates the generation of optimized .elc (byte-compiled) and .eln (native-compiled) files.
- tomorrow-night-deepblue-theme.el: The Tomorrow Night Deepblue Emacs theme is a beautiful deep blue variant of the Tomorrow Night theme, which is renowned for its elegant color palette that is pleasing to the eyes. It features a deep blue background color that creates a calming atmosphere. The theme is also a great choice for those who miss the blue themes that were trendy a few years ago.
- Ultyas: A command-line tool designed to simplify the process of converting code snippets from UltiSnips to YASnippet format.
- dir-config.el: Automatically find and evaluate .dir-config.el Elisp files to configure directory-specific settings.
- flymake-bashate.el: A package that provides a Flymake backend for the bashate Bash script style checker.
- flymake-ansible-lint.el: An Emacs package that offers a Flymake backend for ansible-lint.
- inhibit-mouse.el: A package that disables mouse input in Emacs, offering a simpler and faster alternative to the disable-mouse package.
- quick-sdcv.el: This package enables Emacs to function as an offline dictionary by using the sdcv command-line tool directly within Emacs.
- enhanced-evil-paredit.el: An Emacs package that prevents parenthesis imbalance when using evil-mode with paredit. It intercepts evil-mode commands such as delete, change, and paste, blocking their execution if they would break the parenthetical structure.