Org-babel-eshell

Table of Contents

Motivation

Eshell is Emacs built-in powerful shell. Combine Eshell with Org-mode Babel is great!

Simple execution

Welcome to the Emacs shell

~/install/git/worg/org-contrib/babel/languages $ (setq hello-world "hello, world")
echo $hello-world
hello, world

Support variables assignment

Welcome to the Emacs shell

~/install/git/worg/org-contrib/babel/languages $ echo "hello, " $name
("hello, " "stardiviner")

Support session

Welcome to the Emacs shell

~/install/git/worg/org-contrib/babel/languages $ (setq hello-world "hello, world")
(setq hello-stardiviner "hello, stardiviner")
hello, stardiviner
Welcome to the Emacs shell

~/install/git/worg/org-contrib/babel/languages $ echo $hello-world
hello, world

Source code

;;; ob-eshell.el --- Babel Functions for Eshell            -*- lexical-binding: t; -*-

;; Copyright (C) 2009-2018 Free Software Foundation, Inc.

;; Author: stardiviner <numbchild@gmail.com>
;; Keywords: literate programming, reproducible research
;; Homepage: https://orgmode.org

;; This file is part of GNU Emacs.

;; GNU Emacs 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.

;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; Org Babel support for evaluating Eshell source code.

;;; Code:
(require 'ob)
(require 'eshell)

(defvar org-babel-default-header-args:eshell '())

(defun org-babel-execute:eshell (body params)
  "Execute a block of Eshell code BODY with PARAMS.
This function is called by `org-babel-execute-src-block'.

The BODY can be any code which allowed executed in Eshell.
Eshell allow to execute normal shell command and Elisp code.
More details please reference Eshell Info.

The PARAMS are variables assignments."
  (let* ((session (org-babel-eshell-initiate-session
                   (cdr (assq :session params))))
         (full-body (org-babel-expand-body:generic
                     body params (org-babel-variable-assignments:eshell params))))
    (if session
        (progn
          (with-current-buffer session
            (dolist (line (split-string full-body "\n"))
              (goto-char eshell-last-output-end)
              (insert line)
              (eshell-send-input))
            ;; get output of last input
            ;; TODO: collect all output instead of last command's output.
            (goto-char eshell-last-input-end)
            (buffer-substring-no-properties (point) eshell-last-output-start)))
      (with-temp-buffer
        (eshell-command full-body t)
        (buffer-string)))))

(defun org-babel-prep-session:eshell (session params)
  "Prepare SESSION according to the header arguments specified in PARAMS."
  (let* ((session (org-babel-eshell-initiate-session session))
         ;; Eshell session buffer is read from variable `eshell-buffer-name'.
         (eshell-buffer-name session)
         (var-lines (org-babel-variable-assignments:eshell params)))
    (call-interactively #'eshell)
    (mapc #'eshell-command var-lines)
    session))

(defun ob-eshell-session-live-p (session)
  "Non-nil if Eshell SESSION exists."
  (get-buffer session))

(defun org-babel-eshell-initiate-session (&optional session params)
  "Initiate a session named SESSION according to PARAMS."
  (when (and session (not (string= session "none")))
    (save-window-excursion
      (or (ob-eshell-session-live-p session)
          (progn
            (let ((eshell-buffer-name session))
              (eshell))
            (get-buffer (current-buffer)))))
    session))

(defun org-babel-variable-assignments:eshell (params)
  "Convert ob-eshell :var specified variables into Eshell variables assignments."
  (mapcar
   (lambda (pair)
     (format "(setq %s %S)" (car pair) (cdr pair)))
   (org-babel--get-vars params)))

(defun org-babel-load-session:eshell (session body params)
  "Load BODY into SESSION with PARAMS."
  (save-window-excursion
    (let ((buffer (org-babel-prep-session:eshell session params)))
      (with-current-buffer buffer
        (goto-char (point-max))
        (insert (org-babel-chomp body)))
      buffer)))

(provide 'ob-eshell)

;;; ob-eshell.el ends here

Documentation from the orgmode.org/worg/ website (either in its HTML format or in its Org format) is licensed under the GNU Free Documentation License version 1.3 or later. The code examples and css stylesheets are licensed under the GNU General Public License v3 or later.