--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mylisp/log4-hi-mode.el	Sat Jan 02 00:33:04 2021 +0200
@@ -0,0 +1,92 @@
+;;; log4-hi-mode.el --- Syntax highlighting logs keywords.
+
+;;; Commentary:
+;; Used for highlighting ERROR/WARN/INFO like keywords and dates in logs.
+
+;;; Code:
+
+(defgroup log4-hi nil
+  "`log4-hi-mode' mode for highlighting logs."
+  :prefix "log4-hi-"
+  :group 'text)
+
+(defface log4-hi-error-face
+  '((t :inherit error))
+  "Face for critical message."
+  :group 'log4-hi)
+
+(defface log4-hi-warn-face
+  '((t :inherit warning))
+  "Face for urgent message."
+  :group 'log4-hi)
+
+(defface log4-hi-info-face
+  '((t :inherit success))
+  "Face for informational message."
+  :group 'log4-hi)
+
+(defface log4-hi-func-face
+  '((t :inherit font-lock-function-name-face))
+  "Face for functions in trace."
+  :group 'log4-hi)
+
+(defface log4-hi-time-face
+  '((t :inherit font-lock-builtin-face :height 0.7))
+  "Face for time."
+  :group 'log4-hi)
+
+(defface log4-hi-hide-face
+  '((t :inherit shadow :height 0.7 :family "Arial"))
+  "Face for extra text for hiding."
+  :group 'log4-hi)
+
+(defvar log4-hi-keywords
+  '(("FATAL\\|ERROR" . 'log4-hi-error-face)
+    ("WARN\\|SEVERE" . 'log4-hi-warn-face)
+    ("INFO\\|DEBUG\\|TRACE" . 'log4-hi-info-face) ))
+
+(defvar log4-hi-func-keywords
+  '(("^.\\{0,5\\}at [[:alnum:]./]+\\.\\([[:alnum:]$]+\\.[[:alnum:]$<>]+\\)([[:alnum:]]+\\.java:[0-9]+)" 1 'log4-hi-func-face) )
+  "Highlight regex for line from Java stack trace.")
+
+(defvar log4-hi-time-keywords
+  '(("\\(:?\\(:?[0-9]\\{2\\}?[0-9]\\{2\\}.\\)?[0-9]\\{2\\}.[0-9]\\{2\\}.\\|\\<\\)[0-9]?[0-9]:[0-9][0-9]:[0-9][0-9]\\>\\(:?[.,][0-9]\\{3,6\\}\\)?" . 'log4-hi-time-face))
+  "Highlight regex for ISO date.")
+
+(defvar log4-hi-hide-regex
+  '(("\\[`.\\{3,100\\}`]" . 'log4-hi-hide-face))
+  "Highlight regex for extra text for hiding.")
+
+(defvar log4-hi-func t
+  "Mark to use hilighting of function names in stacktraces. Currently only Java supported.")
+
+(defvar log4-hi-mode-map (make-sparse-keymap)
+  "Keymap for `log4-hi-mode'.")
+
+;;;###autoload
+(define-minor-mode log4-hi-mode
+  "Highlight standard elements in log4* like log-files."
+  nil " log4-hi" log4-hi-mode-map
+  :global nil
+  (catch 'exit
+    (when log4-hi-mode
+      (font-lock-mode 1)
+      (font-lock-add-keywords nil log4-hi-keywords)
+      (font-lock-add-keywords nil log4-hi-time-keywords)
+      (font-lock-add-keywords nil log4-hi-hide-regex)
+      (when log4-hi-func (font-lock-add-keywords nil log4-hi-func-keywords))
+      (setq prettify-symbols-alist (list (cons "[`" ?$,2'f(B) (cons "`]" ?$,2'g(B)))
+      (prettify-symbols-mode 1)
+      (throw 'exit nil))
+    (font-lock-remove-keywords nil log4-hi-keywords)
+    (font-lock-remove-keywords nil log4-hi-time-keywords)
+    (font-lock-remove-keywords nil log4-hi-func-keywords)
+    (font-lock-remove-keywords nil log4-hi-hide-regex)
+    (prettify-symbols-mode -1))
+  (font-lock-flush))
+
+(provide 'log4-hi-mode)
+
+(provide 'log4-hi-mode)
+
+;;; log4-hi-mode.el ends here