On Tue, 8 Nov 2016, Philip Hudson wrote:
[snip]
How do you do "looping" flow control?
For context, what I'm trying to write is a single Org file from which
I can tangle out a number of =~/.ssh/config= files, one for each of
several hosts on a LAN. Within this file I need to repeatedly place a
template =BEGIN_SRC ssh-config= block, each time with a few words and
numbers changed. Do you do this anywhere? If so, how have you
implemented it?
It sounds like what you want is a template for the src block and another src
block that does substitutions in that template using a table of values
inside a loop.
Just to get you started, with this template:
#+NAME: template
#+BEGIN_SRC org
,#+BEGIN_SRC shell :tangle %to-file
ls -lt %filename
,#+END_SRC
#+END_SRC
and this helper src-block
#+NAME: get-body
#+BEGIN_SRC emacs-lisp :var src-block-name="c-code"
(save-excursion
(org-babel-goto-named-src-block
src-block-name)
(cadr (org-babel-get-src-block-info)))
#+END_SRC
running
#+header: :wrap src org :var tmpl=get-body("template")
#+BEGIN_SRC emacs-lisp
(org-fill-template tmpl
'(("to-file" . "abc.sh")("filename" . "my-dir")))
#+END_SRC
yields
#+RESULTS:
#+BEGIN_src org
,#+BEGIN_SRC shell :tangle abc.sh
ls -lt my-dir
,#+END_SRC
#+END_src
To revise this for your application, you need to provide a table of the
associated values for the "to-file" and "filename" keys in the alist, read
that table using a :var header, loop thru the table reconstructing the alist
each time creating src blocks, and send the output to an org tempfile. Then
you tangle the tempfile.
Alternatively, you simply write the script files directly without bothering
to write to an org tempfile.