ob-ledger: Babel support for the ledger accounting system

  Thanks to Eric S Fraga for contributing this support.

  For information on Ledger see
  http://wiki.github.com/jwiegley/ledger/

Makefile

@@ -133,6 +133,7 @@ LISPF      = 	org.el			\
 		ob-dot.el		\
 		ob-mscgen.el		\
 		ob-latex.el		\
+		ob-ledger.el		\
 		ob-python.el		\
 		ob-sql.el		\
 		ob-asymptote.el		\

lisp/ob-ledger.el

@@ -0,0 +1,69 @@
+;;; ob-ledger.el --- org-babel functions for ledger evaluation
+
+;; Copyright (C) 2010  Free Software Foundation, Inc.
+
+;; Author: Eric S Fraga
+;; Keywords: literate programming, reproducible research, accounting
+;; Homepage: http://orgmode.org
+;; Version: 7.01trans
+
+;; 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 evaluating ledger entries.
+;;
+;; This differs from most standard languages in that
+;;
+;; 1) there is no such thing as a "session" in ledger
+;;
+;; 2) we are generally only going to return output from the leger program
+;;
+;; 3) we are adding the "cmdline" header argument
+;;
+;; 4) there are no variables
+
+;;; Code:
+(require 'ob)
+(require 'org)
+
+(defvar org-babel-default-header-args:ledger
+  '((:results . "output") (:cmdline . "bal"))
+  "Default arguments to use when evaluating a ledger source block.")
+
+(defun org-babel-execute:ledger (body params)
+  "Execute a block of Ledger entries with org-babel.  This function is
+called by `org-babel-execute-src-block'."
+  (message "executing Ledger source code block")
+  (let ((result-params (split-string (or (cdr (assoc :results params)) "")))
+	(cmdline (cdr (assoc :cmdline params)))
+        (in-file (make-temp-file "org-babel-ledger"))
+	(out-file (make-temp-file "org-babel-ledger-output"))
+	)
+    (with-temp-file in-file (insert body))
+    (message (concat "ledger -f " in-file " " cmdline))
+    (with-output-to-string
+      (shell-command (concat "ledger -f " in-file " " cmdline " > " out-file)))
+    (with-temp-buffer (insert-file-contents out-file) (buffer-string))))
+
+(defun org-babel-prep-session:ledger (session params)
+  (error "Ledger does not support sessions"))
+
+(provide 'ob-ledger)
+
+;; arch-tag: 7bbb529e-95a1-4236-9d29-b0000b918c7c
+
+;;; ob-ledger.el ends here

lisp/org.el

@@ -159,6 +159,7 @@ requirements) is loaded."
 		 (const :tag "Gnuplot" gnuplot)
 		 (const :tag "Haskell" haskell)
 		 (const :tag "Latex" latex)
+		 (const :tag "Ledger" ledger)
 		 (const :tag "Matlab" matlab)
 		 (const :tag "Mscgen" mscgen)
 		 (const :tag "Ocaml" ocaml)