summaryrefslogtreecommitdiff
path: root/lisp/ob-screen.el
blob: f26337697ae585ec5d6e3d2ab35be7db42bff964 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
;;; ob-screen.el --- org-babel support for interactive terminal

;; Copyright (C) 2009-2013 Free Software Foundation, Inc.

;; Author: Benjamin Andresen
;; Keywords: literate programming, interactive shell
;; Homepage: http://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 <http://www.gnu.org/licenses/>.

;;; 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 'ob)

(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 Babel.
\"default\" session is used when none is specified."
  (message "Sending source code block to interactive terminal session...")
  (save-window-excursion
    (let* ((session (cdr (assoc :session params)))
           (socket (org-babel-screen-session-socketname session)))
      (unless socket (org-babel-prep-session:screen session params))
      (org-babel-screen-session-execute-string
       session (org-babel-expand-body:generic body params)))))

(defun org-babel-prep-session:screen (session params)
  "Prepare SESSION according to the header arguments specified in PARAMS."
  (let* ((session (cdr (assoc :session params)))
         (socket (org-babel-screen-session-socketname session))
         (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 exists, 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 exists by parsing output of \"screen -ls\"."
  (let* ((screen-ls (shell-command-to-string "screen -ls"))
         (sockets (delq
		   nil
                   (mapcar
		    (lambda (x)
		      (when (string-match (rx (or "(Attached)" "(Detached)")) x)
			x))
		    (split-string screen-ls "\n"))))
         (match-socket (car
			(delq
			 nil
			 (mapcar
			  (lambda (x)
			    (when (string-match
				   (concat "org-babel-session-" session) x)
			      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 superfluous spaces
      (goto-char (point-min))
      (delete-matching-lines "^ +$"))
    tmpfile))

(defun org-babel-screen-test ()
  "Test 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 'ob-screen)



;;; ob-screen.el ends here