#+title:      Org Babel: Literate Programming
#+date:       [2024-04-05 Fri]
#+filetags:   :org:babel:
#+identifier: 20240405T140000

* What is Org Babel

Org Babel lets you embed executable code blocks inside org files and run them
directly. Results are captured inline below the block.

* Supported languages

Python, Emacs Lisp, Shell, SQL, R, Julia, Haskell, and dozens more.

#+begin_src emacs-lisp
(org-babel-do-load-languages
 'org-babel-load-languages
 '((python . t)
   (shell . t)
   (sql . t)
   (emacs-lisp . t)))
#+end_src

* Example: Python block

#+begin_src python :results output
words = ["denote", "emacs", "org", "babel"]
for w in words:
    print(w.upper())
#+end_src

* Example: Shell

#+begin_src sh :results output
ls ~/notes/ | head -5
#+end_src

* Tangle: exporting code to files

The =:tangle= header exports the code block to a file on disk.

#+begin_src emacs-lisp :tangle ~/.emacs.d/init.el
(setq inhibit-startup-message t)
(menu-bar-mode -1)
(tool-bar-mode -1)
#+end_src

Running =C-c C-v t= writes the block to the target file.