* The problem
Let's suppose we have this simple code block #+NAME: my-named-code-block #+begin_src bash echo foo-1 echo foo-2 #+end_src which contain some commands that we want to execute before the commands that are presented below. Therefore, we use the =:prologue= header argument #+begin_src bash :noweb yes :prologue "<<my-named-code-block>>" echo a #+end_src However, when evaluating the code block, the buffer =*Org-Babel Error Output*= is opened with the following content. Apparently, this happens because the noweb reference added in the prologue is not expanded. Therefore, =bash= executes =<<foo>>= which results in the error shown below. #+begin_example bash: line 2: warning: here-document at line 1 delimited by end-of-file (wanted `my-named-code-block') bash: line 2: syntax error near unexpected token `newline' bash: line 2: `<<my-named-code-block>>' #+end_example * The question How can I add the content of a code block as the =:prologue= of another code block? * Additional information I don't want to add =<<foo>>= inside the code block (see below for example) since that would imply that the content of the code block is explicitly changed. Note that this doesn't happen when using =:prologue= because it can be set through different ways that don't imply changing the content of the code block where the commands are intended to be executed. #+begin_src bash <<foo>> echo a #+end_src * A possible solution I was thinking in the following solution: Find/Create a function which gets the content of a code block as an string given its name so that it could be called as it follows #+begin_src bash :prologue (get-code-block-as-string "my-named-code-block") echo a #+end_src Recall that this would work because =:prologue= accept strings (see below). #+begin_src bash :prologue "echo foo\necho bar" echo a #+end_src #+RESULTS: #+begin_example foo bar a #+end_example * Relevant information Found the following relevant sources of information [1] A user had asked this in a question in Stack Overflow but he didn't get any significant response. [2] Some user created a thread in the emacs-orgmode mailing list asking why noweb expansion occurs before prologue expansion and presents an example similar to mine. The thread didn't get any response. [3, 4] In a thread in the emacs-orgmode mailing list, this was asked before but the only solution provided was to insert a noweb reference inside the code block. [1] https://stackoverflow.com/questions/50555643/how-to-add-one-code-block-as-prologue-to-another-code-block-for-noweb-style-exp [2] https://lists.gnu.org/archive/html/emacs-orgmode/2019-08/msg00244.html [3] https://lists.gnu.org/archive/html/emacs-orgmode/2020-08/msg00116.html [4] https://lists.gnu.org/archive/html/emacs-orgmode/2020-08/msg00118.html -- Greetings, Rodrigo Morales. IRC: rdrg109 (freenode)
