Hi Ihor,
Follow-on patch so that :var injection occurs after :prologue, which means :var
can now be used on remote hosts if remote host connection occurs via ':prologue
ssh host"
-k.
>From 35eefd3a97dea0d3d8742a0d0a7fb5fce1577deb Mon Sep 17 00:00:00 2001
From: Ken Mankoff <mank...@gmail.com>
Date: Mon, 21 Jul 2025 12:49:43 -0400
Subject: [PATCH 4/4] ob-screen: Support :var on remote hosts by :prologue
after :var
This change supports screen with header :var on remote hosts. It
doesn't yet support :dir /ssh:host: style connections (tramp) but does
support :prologue "ssh host". With the recent addition of ob-screen
supporting :var, the var was injected on the local host, then prologue
executed, meaning var was not seen on the remote host. This patch makes
sure variable injection comes after prologue.
---
etc/ORG-NEWS | 6 ++++--
lisp/org/ob-screen.el | 20 +++++++++++++++-----
2 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index 7091c6b4363..32b88e0b5b3 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -259,10 +259,12 @@ Now, an error is thrown.
*** ob-screen now supports :var header arguments
-The ~:var~ header arg is now supported.
+The ~:var~ header arg is now supported. Var support also works on remote
+hosts if remote hosts are connected to via :prologue
-#+BEGIN_src org
+#+BEGIN_src org :prologue "ssh host"
,#+BEGIN_SRC screen :var x=42
+,hostname
,echo $x
,#+END_SRC
#+END_src
diff --git a/lisp/org/ob-screen.el b/lisp/org/ob-screen.el
index ca2300a96d6..92088becd65 100644
--- a/lisp/org/ob-screen.el
+++ b/lisp/org/ob-screen.el
@@ -57,13 +57,23 @@ org-babel-execute:screen
(save-window-excursion
(let* ((session (cdr (assq :session params)))
(var-lines (org-babel-variable-assignments:screen params))
- (socket (org-babel-screen-session-socketname session)))
+ (socket (org-babel-screen-session-socketname session))
+ (prologue (cdr (assoc :prologue params)))
+ (body-no-prologue (if (and prologue (string-prefix-p prologue body))
+ (string-trim-left body prologue)
+ body)))
(unless socket (org-babel-prep-session:screen session params))
- (mapcar (lambda (var)
- (org-babel-screen-session-execute-string session var))
- var-lines)
+ ;; Send prologue first, if any
+ (when prologue
+ (org-babel-screen-session-execute-string session prologue))
+ ;; Send variable assignments next
+ (mapc (lambda (var)
+ (org-babel-screen-session-execute-string session var))
+ var-lines)
+ ;; Finally, send the rest of the body without prologue
(org-babel-screen-session-execute-string
- session (org-babel-expand-body:generic body params)))))
+ session (org-babel-expand-body:generic body-no-prologue params)))))
+
(defun org-babel-prep-session:screen (_session params)
"Prepare SESSION according to the header arguments specified in PARAMS."
--
2.47.2
