org-babel: add langs/org-babel-screen.el

contrib/babel/lisp/langs/org-babel-screen.el

@@ -0,0 +1,139 @@
+;;; org-babel-screen.el --- org-babel support for interactive terminal
+
+;; Copyright (C) 2009 Benjamin Andresen
+
+;; Author: Benjamin Andresen
+;; Keywords: literate programming, interactive shell
+;; Homepage: http://orgmode.org
+;; Version: 0.01
+
+;;; License:
+
+;; This program 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, or (at your option)
+;; any later version.
+;;
+;; This program 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; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
+
+;;; Commentary:
+
+;; Org-Babel support for interactive terminals. Mostly shell scripts.
+;; Heavily inspired by 'eev' from Eduardo Ochs
+;;
+;; Adding :cmd and :terminal as header arguments
+;; :terminal must support the -T (title) and -e (command) parameter
+;;
+;; You can test the default setup. (xterm + sh) with
+;; M-x org-babel-screen-test RET
+
+;;; Code:
+(require 'org-babel)
+
+(org-babel-add-interpreter "screen")
+
+(add-to-list 'org-src-lang-modes '("screen" . sh))
+
+(defvar org-babel-screen-location "screen"
+  "The command location for screen. 
+In case you want to use a different screen than one selected by your $PATH")
+
+(defvar org-babel-default-header-args:screen
+  '((:results . "silent") (:session . "default") (:cmd . "sh") (:terminal . "xterm"))
+  "Default arguments to use when running screen source blocks.")
+
+(defun org-babel-execute:screen (body params)
+  "Send a block of code via screen to a terminal using org-babel.
+\"default\" session is be used when none is specified."
+  (message "Sending source code block to interactive terminal session...")
+  (save-window-excursion
+    (let ((socket (org-babel-screen-session-socketname session)))
+      (unless socket (org-babel-prep-session:screen session params))
+      (org-babel-screen-session-execute-string session body))))
+
+(defun org-babel-prep-session:screen (session params)
+  "Prepare SESSION according to the header arguments specified in PARAMS."
+  (let* ((socket (org-babel-screen-session-socketname session))
+         (vars (org-babel-ref-variables params))
+         (cmd (cdr (assoc :cmd params)))
+         (terminal (cdr (assoc :terminal params)))
+         (process-name (concat "org-babel: terminal (" session ")")))
+    (apply 'start-process process-name "*Messages*"
+           terminal `("-T" ,(concat "org-babel: " session) "-e" ,org-babel-screen-location
+                           "-c" "/dev/null" "-mS" ,(concat "org-babel-session-" session)
+                           ,cmd))
+    ;; XXX: Is there a better way than the following?
+    (while (not (org-babel-screen-session-socketname session))
+      ;; wait until screen session is available before returning
+      )))
+
+;; helper functions
+
+(defun org-babel-screen-session-execute-string (session body)
+  "If SESSION exist, send BODY to it."
+  (let ((socket (org-babel-screen-session-socketname session)))
+    (when socket
+      (let ((tmpfile (org-babel-screen-session-write-temp-file session body)))
+        (apply 'start-process (concat "org-babel: screen (" session ")") "*Messages*"
+               org-babel-screen-location
+               `("-S" ,socket "-X" "eval" "msgwait 0"
+                      ,(concat "readreg z " tmpfile)
+                      "paste z"))))))
+
+(defun org-babel-screen-session-socketname (session)
+  "Check if SESSION exist by parsing output of \"screen -ls\"."
+  (let* ((screen-ls (shell-command-to-string "screen -ls"))
+         (sockets (remove-if-not
+                   '(lambda (x)
+                     (string-match (rx (or "(Attached)" "(Detached)")) x))
+                   (split-string screen-ls "\n")))
+         (match-socket (find-if
+                        '(lambda (x)
+                          (string-match (concat "org-babel-session-" session) x))
+                        sockets)))
+    (when match-socket (car (split-string match-socket)))))
+
+(defun org-babel-screen-session-write-temp-file (session body)
+  "Save BODY in a temp file that is named after SESSION."
+  (let ((tmpfile (concat "/tmp/screen.org-babel-session-" session)))
+    (with-temp-file tmpfile
+      (insert body)
+
+      ;; org-babel has superflous spaces
+      (goto-char (point-min))
+      (delete-matching-lines "^ +$"))
+    tmpfile))
+
+(defun org-babel-screen-test ()
+  "Command that tests if the default setup works. 
+The terminal should shortly flicker."
+  (interactive)
+  (let* ((session "org-babel-testing")
+         (random-string (format "%s" (random 99999)))
+         (tmpfile "/tmp/org-babel-screen.test")
+         (body (concat "echo '" random-string "' > " tmpfile "\nexit\n"))
+         process tmp-string)
+    (org-babel-execute:screen body org-babel-default-header-args:screen)
+    ;; XXX: need to find a better way to do the following
+    (while (not (file-readable-p tmpfile))
+      ;; do something, otherwise this will be optimized away
+      (format "org-babel-screen: File not readable yet."))
+    (setq tmp-string (with-temp-buffer
+                       (insert-file-contents-literally tmpfile)
+                       (buffer-substring (point-min) (point-max))))
+    (delete-file tmpfile)
+    (message (concat "org-babel-screen: Setup "
+                     (if (string-match random-string tmp-string)
+                         "WORKS."
+                         "DOESN'T work.")))))
+
+(provide 'org-babel-screen)
+;;; org-babel-screen.el ends here