From bc8103b8f8bca1706ec9ee0dd0cdfa1621987438 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20N=C3=A1jera?= <hi@oscarnajera.com>
Date: Wed, 7 Sep 2022 23:19:38 +0200
Subject: journalctl cleanup buffer

---
 elisp/journalctl.el | 45 ++++++++++++++++++++++++---------------------
 1 file changed, 24 insertions(+), 21 deletions(-)

diff --git a/elisp/journalctl.el b/elisp/journalctl.el
index fd6582c..f36ebc1 100644
--- a/elisp/journalctl.el
+++ b/elisp/journalctl.el
@@ -123,9 +123,19 @@
     "--boot"
     "--since"
     "--until"
+    "--user"
     "--priority")
   "List of possible options to be given to journalctl." )
 
+(defun journalctl--clean-buffer ()
+  "Produce a clean buffer for the log.
+It seems I must kill the buffer for tramp to behave correctly on the new calls."
+  (let* ((name-buffer "JOURNAL LOG")
+         (buffer (get-buffer name-buffer)))
+    (when (buffer-live-p buffer)
+      (kill-buffer buffer))
+    (get-buffer-create name-buffer)))
+
 (defun journalctl-system-units (host-location)
   "Query HOST-LOCATION (a tramp path) for its systemd units."
   (interactive (list (completing-read "Tramp host: " journalctl-hosts)))
@@ -138,46 +148,40 @@
                    (delq nil)
                    (completing-read "Unit: ")))))
 
-
 (defun journalctl (host options)
   "Query the log of HOST given OPTIONS."
   (interactive
    (let* ((picked-host (completing-read "Tramp host: " journalctl-hosts))
           (default-options `(("--unit" ,(journalctl-system-units picked-host)) ("--follow"))))
      (list picked-host default-options)))
-  (let ((buffer (get-buffer-create "JOURNAL LOG"))
+  (let ((buffer (journalctl--clean-buffer))
         (default-directory host))
     (apply #'start-file-process "Journal" buffer "journalctl" (flatten-tree options))
     (with-current-buffer buffer
       (journalctl-mode)
       (setq-local journalctl-current-host host)
-      (setq-local journalctl-current-opts options)
-      (switch-to-buffer (current-buffer)))))
+      (setq-local journalctl-current-opts options))
+    (switch-to-buffer buffer)))
 
 (defun journalctl-remove-opt (opt)
-  "Remove option from journalctl call.
-
-If OPT is set, remove this option."
+  "Remove an OPT flag from the journal query."
   (interactive (list (completing-read "remove option" (mapcar #'car journalctl-current-opts) nil t)))
   (let ((new-opts (delq (assoc opt journalctl-current-opts) journalctl-current-opts))
         (host journalctl-current-host))
-    (kill-buffer (get-buffer "JOURNAL LOG"))
     (journalctl host new-opts)))
 
-
 (defun journalctl-add-opt (opt)
   "Remove option from journalctl call.
 
 If OPT is set, remove this option."
-  (interactive (list (completing-read "add option" journalctl-list-of-options nil t)))
-  (let* ((buff (get-buffer "JOURNAL LOG"))
-         (opts (delq (assoc opt journalctl-current-opts) journalctl-current-opts))
-         (host journalctl-current-host))
-    (kill-buffer buff)
+  (interactive (list (completing-read "add option: " journalctl-list-of-options nil t)))
+  (let ((opts (delq (assoc opt journalctl-current-opts) journalctl-current-opts))
+        (host journalctl-current-host))
     (thread-last
       (pcase opt
         ((or "--since" "--until") (org-read-date t))
-        ((or "--follow" "--reverse"))
+        ((or "--follow" "--reverse" "--user"))
+        ("--unit" (journalctl-system-units host))
         (_ (read-string (concat opt "= "))))
       (list opt)
       (list)
@@ -187,20 +191,19 @@ If OPT is set, remove this option."
 (defun  journalctl-edit-opts ()
   "Edit the value of 'journalctl-current-opts'."
   (interactive)
-  (let* ((buff (get-buffer "JOURNAL LOG"))
-         (host journalctl-current-host)
-         (opts (when buff (with-current-buffer buff journalctl-current-opts))))
-    (with-current-buffer (get-buffer-create "Edit Journalctl options")
+  (let* ((host journalctl-current-host)
+         (opts journalctl-current-opts)
+         (edit-buff (get-buffer-create "Edit Journalctl options")))
+    (with-current-buffer edit-buff
       (emacs-lisp-mode)
       (cl-prettyprint opts)
       (local-set-key "\C-c\C-c"
                      (lambda ()
                        (interactive)
                        (goto-char (point-min))
-                       (kill-buffer buff)
                        (let ((standard-input (current-buffer)))
                          (journalctl host (read)))
-                       (kill-buffer)))
+                       (kill-buffer edit-buff)))
       (switch-to-buffer (current-buffer)))))
 
 
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