lisp/ob-screen.el

   1 ;;; ob-screen.el --- org-babel support for interactive terminal
   2
   3 ;; Copyright (C) 2009-2013 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 (require 'ob-ref)
  38
  39 (defvar org-babel-screen-location "screen"
  40   "The command location for screen.
  41 In case you want to use a different screen than one selected by your $PATH")
  42
  43 (defvar org-babel-default-header-args:screen
  44   '((:results . "silent") (:session . "default") (:cmd . "sh") (:terminal . "xterm"))
  45   "Default arguments to use when running screen source blocks.")
  46
  47 (defun org-babel-execute:screen (body params)
  48   "Send a block of code via screen to a terminal using Babel.
  49 \"default\" session is used when none is specified."
  50   (message "Sending source code block to interactive terminal session...")
  51   (save-window-excursion
  52     (let* ((session (cdr (assoc :session params)))
  53            (socket (org-babel-screen-session-socketname session)))
  54       (unless socket (org-babel-prep-session:screen session params))
  55       (org-babel-screen-session-execute-string
  56        session (org-babel-expand-body:generic body params)))))
  57
  58 (defun org-babel-prep-session:screen (session params)
  59   "Prepare SESSION according to the header arguments specified in PARAMS."
  60   (let* ((session (cdr (assoc :session params)))
  61          (socket (org-babel-screen-session-socketname session))
  62          (cmd (cdr (assoc :cmd params)))
  63          (terminal (cdr (assoc :terminal params)))
  64          (process-name (concat "org-babel: terminal (" session ")")))
  65     (apply 'start-process process-name "*Messages*"
  66            terminal `("-T" ,(concat "org-babel: " session) "-e" ,org-babel-screen-location
  67                       "-c" "/dev/null" "-mS" ,(concat "org-babel-session-" session)
  68                       ,cmd))
  69     ;; XXX: Is there a better way than the following?
  70     (while (not (org-babel-screen-session-socketname session))
  71       ;; wait until screen session is available before returning
  72       )))
  73
  74 ;; helper functions
  75
  76 (defun org-babel-screen-session-execute-string (session body)
  77   "If SESSION exists, send BODY to it."
  78   (let ((socket (org-babel-screen-session-socketname session)))
  79     (when socket
  80       (let ((tmpfile (org-babel-screen-session-write-temp-file session body)))
  81         (apply 'start-process (concat "org-babel: screen (" session ")") "*Messages*"
  82                org-babel-screen-location
  83                `("-S" ,socket "-X" "eval" "msgwait 0"
  84                  ,(concat "readreg z " tmpfile)
  85                  "paste z"))))))
  86
  87 (defun org-babel-screen-session-socketname (session)
  88   "Check if SESSION exists by parsing output of \"screen -ls\"."
  89   (let* ((screen-ls (shell-command-to-string "screen -ls"))
  90          (sockets (delq
  91                    nil
  92                    (mapcar
  93                     (lambda (x)
  94                       (when (string-match (rx (or "(Attached)" "(Detached)")) x)
  95                         x))
  96                     (split-string screen-ls "\n"))))
  97          (match-socket (car
  98                         (delq
  99                          nil
 100                          (mapcar
 101                           (lambda (x)
 102                             (when (string-match
 103                                    (concat "org-babel-session-" session) x)
 104                               x))
 105                           sockets)))))
 106     (when match-socket (car (split-string match-socket)))))
 107
 108 (defun org-babel-screen-session-write-temp-file (session body)
 109   "Save BODY in a temp file that is named after SESSION."
 110   (let ((tmpfile (concat "/tmp/screen.org-babel-session-" session)))
 111     (with-temp-file tmpfile
 112       (insert body)
 113
 114       ;; org-babel has superfluous spaces
 115       (goto-char (point-min))
 116       (delete-matching-lines "^ +$"))
 117     tmpfile))
 118
 119 (defun org-babel-screen-test ()
 120   "Test if the default setup works.
 121 The terminal should shortly flicker."
 122   (interactive)
 123   (let* ((session "org-babel-testing")
 124          (random-string (format "%s" (random 99999)))
 125          (tmpfile "/tmp/org-babel-screen.test")
 126          (body (concat "echo '" random-string "' > " tmpfile "\nexit\n"))
 127          process tmp-string)
 128     (org-babel-execute:screen body org-babel-default-header-args:screen)
 129     ;; XXX: need to find a better way to do the following
 130     (while (not (file-readable-p tmpfile))
 131       ;; do something, otherwise this will be optimized away
 132       (format "org-babel-screen: File not readable yet."))
 133     (setq tmp-string (with-temp-buffer
 134                        (insert-file-contents-literally tmpfile)
 135                        (buffer-substring (point-min) (point-max))))
 136     (delete-file tmpfile)
 137     (message (concat "org-babel-screen: Setup "
 138                      (if (string-match random-string tmp-string)
 139                          "WORKS."
 140                        "DOESN'T work.")))))
 141
 142 (provide 'ob-screen)
 143
 144
 145
 146 ;;; ob-screen.el ends here