mpv: printout marked files using the "M" key similar to sxiv

.config/mpv/scripts/mark.lua

@@ -0,0 +1,30 @@
+-- mpv script to mark videos
+local utils = require 'mp.utils'
+local marked_videos = {}
+local marked_file = "marked"
+
+function toggle_mark()
+    local path = mp.get_property("path")
+    if marked_videos[path] then
+        marked_videos[path] = nil
+        mp.osd_message("Unmarked: " .. path)
+    else
+        marked_videos[path] = true
+        mp.osd_message("Marked: " .. path)
+    end
+end
+
+function save_marks()
+    -- Do not write anything if "marked_videos" is empty
+    if next(marked_videos) == nil then
+	return
+    end
+    local file = io.open(marked_file, "a")
+    for path, _ in pairs(marked_videos) do
+        file:write(path .. "\n")
+    end
+    file:close()
+end
+
+mp.add_key_binding("M", "toggle_mark", toggle_mark)
+mp.register_event("shutdown", save_marks)