org-mode/testing/examples/babel.org

#+Title: a collection of examples for Babel tests

* =:noweb= header argument expansion
  :PROPERTIES:
  :ID:       eb1f6498-5bd9-45e0-9c56-50717053e7b7
  :END:

#+source: noweb-example
#+begin_src emacs-lisp
  (message "expanded")
#+end_src

#+begin_src emacs-lisp :noweb yes
  ;; noweb-yes-start
  <<noweb-example>>
  ;; noweb-yes-end
#+end_src

#+begin_src emacs-lisp :noweb no
  ;; noweb-no-start
  <<noweb-example>>
  ;; noweb-no-end
#+end_src

#+begin_src emacs-lisp :noweb tangle
  ;; noweb-tangle-start
  <<noweb-example>>
  ;; noweb-tangle-end
#+end_src

* elisp forms in header arguments
  :PROPERTIES:
  :ID:       22d67284-bf14-4cdc-8319-f4bd876829d7
  :var:      prop=(+ 2 2)
  :END:

#+begin_src emacs-lisp
  prop
#+end_src

#+results:
: 4

* excessive id links on tangling
  :PROPERTIES:
  :ID:       ef06fd7f-012b-4fde-87a2-2ae91504ea7e
  :END:

** no, don't give me an ID
#+begin_src emacs-lisp :tangle no
  (message "not to be tangled")
#+end_src

** yes, I'd love an ID
   :PROPERTIES:
   :ID:       ae7b55ca-9ef2-4d30-bd48-da30e35fd0f3
   :END:
#+begin_src emacs-lisp :tangle no
  (message "for tangling")
#+end_src
* simple variable resolution
  :PROPERTIES:
  :ID:       f68821bc-7f49-4389-85b5-914791ee3718
  :END:

#+source: four
#+begin_src emacs-lisp
  (list 1 2 3 4)
#+end_src

#+begin_src emacs-lisp :var four=four
  (length four)
#+end_src

#+results:
: 4

* multi-line header arguments
  :PROPERTIES:
  :ID:       b77c8857-6c76-4ea9-8a61-ddc2648d96c4
  :END:

#+headers: :var letters='(a b c d e f g)
#+begin_src emacs-lisp :var numbers='(1 2 3 4 5 6 7)
  (map 'list #'list numbers letters)
#+end_src

#+results:
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | d |
| 5 | e |
| 6 | f |
| 7 | g |

* simple named code block
  :PROPERTIES:
  :ID:       0d82b52d-1bb9-4916-816b-2c67c8108dbb
  :END:

#+source: i-have-a-name
#+begin_src emacs-lisp
  42
#+end_src

#+results: 
: 42

#+results: i-have-a-name
: 42

* Pascal's Triangle -- export test
  :PROPERTIES:
  :ID:       92518f2a-a46a-4205-a3ab-bcce1008a4bb
  :END:

#+source: pascals-triangle
#+begin_src emacs-lisp :var n=5 :exports both
  (defun pascals-triangle (n)
    (if (= n 0)
        (list (list 1))
      (let* ((prev-triangle (pascals-triangle (- n 1)))
             (prev-row (car (reverse prev-triangle))))
        (append prev-triangle
                (list (map 'list #'+
                           (append prev-row '(0))
                           (append '(0) prev-row)))))))

  (pascals-triangle n)
#+end_src

* calling code blocks from inside table
  :PROPERTIES:
  :ID:       6d2ff4ce-4489-4e2a-9c65-e3f71f77d975
  :END:

#+source: take-sqrt
#+begin_src emacs-lisp :var n=9
  (sqrt n)
#+end_src

* executing an lob call line
  :PROPERTIES:
  :results:  silent
  :ID:       fab7e291-fde6-45fc-bf6e-a485b8bca2f0
  :END:

#+call: echo(input="testing")
#+call: echo(input="testing") :results vector
#+call: echo[:var input="testing"]()
#+call: echo[:var input="testing"]() :results vector
#+call: echo("testing")
#+call: echo("testing") :results vector

* parsing header arguments
  :PROPERTIES:
  :ID:       7eb0dc6e-1c53-4275-88b3-b22f3113b9c3
  :END:

#+begin_src example-lang :session     :results output :var num=9
  the body
#+end_src
* conflicting blocks on export
  :PROPERTIES:
  :ID:       5daa4d03-e3ea-46b7-b093-62c1b7632df3
  :END:
#+results: a-list
- a
- b
- c

#+begin_src emacs-lisp :results wrap :exports both
    "code block results"
#+end_src
#+begin_src emacs-lisp :var lst=a-list :results list
  (reverse lst)
#+end_src
* using the =:noweb-ref= header argument
  :PROPERTIES:
  :ID:       54d68d4b-1544-4745-85ab-4f03b3cbd8a0
  :END:

#+begin_src sh :tangle yes :noweb yes :shebang #!/bin/sh
  <<fullest-disk>>
#+end_src

** query all mounted disks
#+begin_src sh :noweb-ref fullest-disk
  df \
#+end_src

** strip the header row
#+begin_src sh :noweb-ref fullest-disk
  |sed '1d' \
#+end_src

** sort by the percent full
#+begin_src sh :noweb-ref fullest-disk
  |awk '{print $5 " " $6}'|sort -n |tail -1 \
#+end_src

** extract the mount point
#+begin_src sh :noweb-ref fullest-disk
  |awk '{print $2}'
#+end_src