EmacsWiki: Eshell Completion (original) (raw)
Customization
Eshell offers you completion of filenames. If several filenames are possible, the most recently modified file will be used first.
This is determined by ‘eshell-cmpl-compare-entry-function’ and defaults to ‘file-newer-than-file-p’. The idea is that once you start working with a certain file, you will want it to appear first in your completion list.
Here’s some untested code to reverse this order, and to take ‘completion-ignored-extensions’ into account.
(setq eshell-cmpl-compare-entry-function (function (lambda (left right) (let ((exts completion-ignored-extensions) found) (while exts (if (string-match (concat "\" (car exts) "$") right) (setq found t exts nil)) (setq exts (cdr exts))) (if found nil (file-newer-than-file-p left right))))))
Contributors: KaiGrossjohann, JohnWiegley
Remote Files
If I want to change directory to /scratch, then pressing TAB after typing “cd /sc” leads to TrampMode trying to open a connection. This is because the tramp-completion-file-name-handler entry in file-name-handler-alist leads to:
(file-name-all-completions "sc" "/") => ("scpx:" "scp2_old:" "scp1_old:" "scp2:" "scp1:" "scp:" "scratch/")
and pcomplete tries to run file-directory-p on all these entries.
One way to avoid this is to use the following:
(defadvice pcomplete (around avoid-remote-connections activate) (let ((file-name-handler-alist (copy-alist file-name-handler-alist))) (setq file-name-handler-alist (delete (rassoc 'tramp-completion-file-name-handler file-name-handler-alist) file-name-handler-alist)) ad-do-it))
Note that completion of “cd _su::_” still works because this is handled by tramp-file-name-handler.
Perhaps there are better ways of doing this? – Matt Hodges
Subcommand completions
In default subcommands are not completed, so I make the completion functions for the commands (systemctl, sudo, man) which have subcommands. Completion functions have the corresponding commands’ names.
(defun pcomplete/sudo () "Completion rules for the `sudo' command." (let ((pcomplete-ignore-case t)) (pcomplete-here (funcall pcomplete-command-completion-function)) (while (pcomplete-here (pcomplete-entries)))))
(defcustom pcomplete-systemctl-commands '("disable" "enable" "status" "start" "restart" "stop" "reenable" "list-units" "list-unit-files") "p-completion candidates for `systemctl' main commands" :type '(repeat (string :tag "systemctl command")) :group 'pcomplete)
(defvar pcomplete-systemd-units (split-string (shell-command-to-string "(systemctl list-units --all --full --no-legend)) "p-completion candidates for all `systemd' units")
(defvar pcomplete-systemd-user-units (split-string (shell-command-to-string "(systemctl list-units --user --all --full --no-legend)) "p-completion candidates for all `systemd' user units")
(defun pcomplete/systemctl () "Completion rules for the `systemctl' command." (pcomplete-here (append pcomplete-systemctl-commands '("--user"))) (cond ((pcomplete-test "--user") (pcomplete-here pcomplete-systemctl-commands) (pcomplete-here pcomplete-systemd-user-units)) (t (pcomplete-here pcomplete-systemd-units))))
(defvar pcomplete-man-user-commands (split-string (shell-command-to-string "apropos -s 1 .|while read -r a b)) "p-completion candidates for `man' command")
(defun pcomplete/man () "Completion rules for the `man' command." (pcomplete-here pcomplete-man-user-commands))
Completed subcommands on systemctl are set disable, enable, status, start, restart, stop, but if needed, you can add other subcommands.
Miscellaneous
If I set my own prompt, like this:
(setq eshell-prompt-function (lambda () (concat "[" (user-login-name) "@" (system-name) " " (eshell/pwd) "]" (if (= (user-uid) 0) "# " "$ "))))
completion stops working. When I press tab, I get the message “Text is read-only”. Can anyone explain this? – bkhl
This happens because you haven’t modified eshell-prompt-regexp accordingly (see the documentation for eshell-prompt-function). This should work:
(setq eshell-prompt-regexp "^[^#$\n]*[#$] ")
See EshellFunctions for more examples. – MattHodges
Ok, thanks. I like pcomplete-list better than the completion cycling. I tried this:
(add-hook 'eshell-mode-hook '(lambda () (define-key eshell-mode-map "\t" 'pcomplete-list)))
but it doesn’t work. How should this be done properly? – bkhl
I use:
(setq eshell-cmpl-cycle-completions nil)
to avoid completion cycling. – MattHodges
AutoComplete
I use the amazing AutoComplete package for completion. Eshell provides completion through the ProgrammableCompletion package. I did not found a suitable auto-complete source for pcomplete, so I use the following code:
(defun ac-pcomplete ()
;; eshell uses insert-and-inherit' to insert a \t if no completion ;; can be found, but this must not happen as auto-complete source (flet ((insert-and-inherit (&rest args))) ;; this code is stolen from pcomplete' in pcomplete.el
(let* (tramp-mode ;; do not automatically complete remote stuff
(pcomplete-stub)
(pcomplete-show-list t) ;; inhibit patterns like * being deleted
pcomplete-seen pcomplete-norm-func
pcomplete-args pcomplete-last pcomplete-index
(pcomplete-autolist pcomplete-autolist)
(pcomplete-suffix-list pcomplete-suffix-list)
(candidates (pcomplete-completions))
(beg (pcomplete-begin))
;; note, buffer text and completion argument may be
;; different because the buffer text may bet transformed
;; before being completed (e.g. variables like $HOME may be
;; expanded)
(buftext (buffer-substring beg (point)))
(arg (nth pcomplete-index pcomplete-args)))
;; we auto-complete only if the stub is non-empty and matches
;; the end of the buffer text
(when (and (not (zerop (length pcomplete-stub)))
(or (string= pcomplete-stub ; Emacs 23
(substring buftext
(max 0
(- (length buftext)
(length pcomplete-stub)))))
(string= pcomplete-stub ; Emacs 24
(substring arg
(max 0
(- (length arg)
(length pcomplete-stub)))))))
;; Collect all possible completions for the stub. Note that
;; candidates may be a function, that's why we use
;; all-completions.
(let* ((cnds (all-completions pcomplete-stub candidates))
(bnds (completion-boundaries pcomplete-stub
candidates
nil
""))
(skip (- (length pcomplete-stub) (car bnds))))
;; We replace the stub at the beginning of each candidate by
;; the real buffer content.
(mapcar #'(lambda (cand) (concat buftext (substring cand skip)))
cnds))))))
(defvar ac-source-pcomplete '((candidates . ac-pcomplete)))
(add-hook 'eshell-mode-hook #'(lambda () (setq ac-sources '(ac-source-pcomplete)))) (add-to-list 'ac-modes 'eshell-mode)