Fish-like history autosuggestions in eshell
[[demo.gif]]
** Installation This package is on melpa. If you have melpa in your package repositories, you can use ~M-x RET package-install RET esh-autosuggest~ or install with [[https://github.com/jwiegley/use-package][use-package]]:
(use-package esh-autosuggest :hook (eshell-mode . esh-autosuggest-mode) ;; If you have use-package-hook-name-suffix set to nil, uncomment and use the ;; line below instead: ;; :hook (eshell-mode-hook . esh-autosuggest-mode) :ensure t)
Alternatively, consider installing with [[https://github.com/raxod502/straight.el][straight.el]] or [[https://github.com/quelpa/quelpa-use-package][quelpa-use-package]].
Otherwise, download the files to somewhere on your load path, and require esh-autosuggest:
(require 'esh-autosuggest)
** Usage This package assumes you use something other than company for eshell completion (e.g. ~eshell-pcomplete~, ~completion-at-point~, ~helm-esh-pcomplete~). ~company-mode~ is used solely as a mechanism for history autosuggestions.
Unless you're using use-package's hook keyword as described in Installation, you can enable the autosuggestions with:
(add-hook 'eshell-mode-hook #'esh-autosuggest-mode)
*** Key Bindings
Keys can be modified using ~esh-autosuggest-active-map~.
If instead you don't want ~company-active-map~ to be overridden, you may set ~esh-autosuggest-use-company-map~ to ~t~. This may cause unexpected behavior when pressing ~RET~ or ~TAB~, depending on what you want those to do. To emulate fish-shell most closely, it is recommended you leave this ~nil~, as that will explicitly run your input (regardless of suggestion) on ~RET~, and bring up your preferred completion system on ~TAB~.
*** Delay ~esh-autosuggest-delay~ defaults to 0 seconds. This is most like fish shell's instant history autosuggestions, but can be customized.
*** With other backends (not recommended) It is technically possible to group this backend with other company backends like e.g. ~company-capf~ like so:
;; don't add esh-autosuggest-mode to eshell-mode-hook (defun setup-eshell-grouped-backends () (setq-local company-backends '((company-capf esh-autosuggest))))
(add-hook 'eshell-mode-hook #'setup-eshell-grouped-backends)
This isn't recommended since the history suggestions will be neither fish-like, nor will they work after typing the first word on the command line, since company-backends need to share a prefix to work together smoothly. See [[https://github.com/company-mode/company-mode/issues/744][company-mode/company-mode#744]] for more information.
*** Known bugs and workarounds If you're using [[https://github.com/emacs-evil/evil-collection][evil-collection]], there's a [[https://github.com/dieggsy/esh-autosuggest/issues/12][known issue]] that occurs when ~evil-collection-company-use-tng~ is set to ~t~ (the default). If you don't need that feature, you can set it to ~nil~ for the time being.
** Rationale and tips I made this package to help ease a transition from zsh to eshell as my main shell. The reason the main mechanism is a minor-mode that overrides company-mode is that I didn't find company-mode that useful for eshell completion.
While the default popup-buffer frontend to pcomplete can be a bit annoying, I've found there are alternatives that make pcomplete behave more like normal shell completion. Try one or more of the following for tab completion:
If you use helm
(defun setup-eshell-helm-completion () (define-key eshell-mode-map [remap eshell-pcomplete] 'helm-esh-pcomplete))
(add-hook 'eshell-mode-hook #'setup-eshell-helm-completion)
If you use ivy
(setq ivy-do-completion-in-region t) ; this is the default
(defun setup-eshell-ivy-completion () (define-key eshell-mode-map [remap eshell-pcomplete] 'completion-at-point) ;; only if you want to use the minibuffer for completions instead of the ;; in-buffer interface (setq-local ivy-display-functions-alist (remq (assoc 'ivy-completion-in-region ivy-display-functions-alist) ivy-display-functions-alist)))
(add-hook 'eshell-mode-hook #'setup-eshell-ivy-completion)