lisp/ob-screen.el

   1 ;;; ob-screen.el --- org-babel support for interactive terminal
   2
   3 ;; Copyright (C) 2009-2015 Free Software Foundation, Inc.
   4
   5 ;; Author: Benjamin Andresen
   6 ;; Keywords: literate programming, interactive shell
   7 ;; Homepage: http://orgmode.org
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; Org-Babel support for interactive terminals.  Mostly shell scripts.
  27 ;; Heavily inspired by 'eev' from Eduardo Ochs
  28 ;;
  29 ;; Adding :cmd and :terminal as header arguments
  30 ;; :terminal must support the -T (title) and -e (command) parameter
  31 ;;
  32 ;; You can test the default setup. (xterm + sh) with
  33 ;; M-x org-babel-screen-test RET
  34
  35 ;;; Code:
  36 (require 'ob)
  37
  38 (defvar org-babel-screen-location "screen"
  39   "The command location for screen.
  40 In case you want to use a different screen than one selected by your $PATH")
  41
  42 (defvar org-babel-default-header-args:screen
  43   '((:results . "silent") (:session . "default") (:cmd . "sh") (:terminal . "xterm"))
  44   "Default arguments to use when running screen source blocks.")
  45
  46 (defun org-babel-execute:screen (body params)
  47   "Send a block of code via screen to a terminal using Babel.
  48 \"default\" session is used when none is specified."
  49   (message "Sending source code block to interactive terminal session...")
  50   (save-window-excursion
  51     (let* ((session (cdr (assoc :session params)))
  52            (socket (org-babel-screen-session-socketname session)))
  53       (unless socket (org-babel-prep-session:screen session params))
  54       (org-babel-screen-session-execute-string
  55        session (org-babel-expand-body:generic body params)))))
  56
  57 (defun org-babel-prep-session:screen (session params)
  58   "Prepare SESSION according to the header arguments specified in PARAMS."
  59   (let* ((session (cdr (assoc :session params)))
  60          (socket (org-babel-screen-session-socketname session))
  61          (cmd (cdr (assoc :cmd params)))
  62          (terminal (cdr (assoc :terminal params)))
  63          (process-name (concat "org-babel: terminal (" session ")")))
  64     (apply 'start-process process-name "*Messages*"
  65            terminal `("-T" ,(concat "org-babel: " session) "-e" ,org-babel-screen-location
  66                       "-c" "/dev/null" "-mS" ,(concat "org-babel-session-" session)
  67                       ,cmd))
  68     ;; XXX: Is there a better way than the following?
  69     (while (not (org-babel-screen-session-socketname session))
  70       ;; wait until screen session is available before returning
  71       )))
  72
  73 ;; helper functions
  74
  75 (defun org-babel-screen-session-execute-string (session body)
  76   "If SESSION exists, send BODY to it."
  77   (let ((socket (org-babel-screen-session-socketname session)))
  78     (when socket
  79       (let ((tmpfile (org-babel-screen-session-write-temp-file session body)))
  80         (apply 'start-process (concat "org-babel: screen (" session ")") "*Messages*"
  81                org-babel-screen-location
  82                `("-S" ,socket "-X" "eval" "msgwait 0"
  83                  ,(concat "readreg z " tmpfile)
  84                  "paste z"))))))
  85
  86 (defun org-babel-screen-session-socketname (session)
  87   "Check if SESSION exists by parsing output of \"screen -ls\"."
  88   (let* ((screen-ls (shell-command-to-string "screen -ls"))
  89          (sockets (delq
  90                    nil
  91                    (mapcar
  92                     (lambda (x)
  93                       (when (string-match (rx (or "(Attached)" "(Detached)")) x)
  94                         x))
  95                     (split-string screen-ls "\n"))))
  96          (match-socket (car
  97                         (delq
  98                          nil
  99                          (mapcar
 100                           (lambda (x)
 101                             (when (string-match
 102                                    (concat "org-babel-session-" session) x)
 103                               x))
 104                           sockets)))))
 105     (when match-socket (car (split-string match-socket)))))
 106
 107 (defun org-babel-screen-session-write-temp-file (session body)
 108   "Save BODY in a temp file that is named after SESSION."
 109   (let ((tmpfile (org-babel-temp-file "screen-")))
 110     (with-temp-file tmpfile
 111       (insert body)
 112
 113       ;; org-babel has superfluous spaces
 114       (goto-char (point-min))
 115       (delete-matching-lines "^ +$"))
 116     tmpfile))
 117
 118 (defun org-babel-screen-test ()
 119   "Test if the default setup works.
 120 The terminal should shortly flicker."
 121   (interactive)
 122   (let* ((session "org-babel-testing")
 123          (random-string (format "%s" (random 99999)))
 124          (tmpfile (org-babel-temp-file "ob-screen-test-"))
 125          (body (concat "echo '" random-string "' > " tmpfile "\nexit\n"))
 126          process tmp-string)
 127     (org-babel-execute:screen body org-babel-default-header-args:screen)
 128     ;; XXX: need to find a better way to do the following
 129     (while (not (file-readable-p tmpfile))
 130       ;; do something, otherwise this will be optimized away
 131       (format "org-babel-screen: File not readable yet."))
 132     (setq tmp-string (with-temp-buffer
 133                        (insert-file-contents-literally tmpfile)
 134                        (buffer-substring (point-min) (point-max))))
 135     (delete-file tmpfile)
 136     (message (concat "org-babel-screen: Setup "
 137                      (if (string-match random-string tmp-string)
 138                          "WORKS."
 139                        "DOESN'T work.")))))
 140
 141 (provide 'ob-screen)
 142
 143
 144
 145 ;;; ob-screen.el ends here