How to pass arbitrary number of arguments from script-message to Lua plugin?

[enoryw]

I currently have a binding that runs the trash-video shell script on the video with arguments -bnt <video> passed as arguments, then removes it from the playlist.

DEL run trash-video -bnt "${path}"; playlist-remove current

It seems to sometimes have issues with playlist-remove current running too soon before trash-video is able to run (I suppose trash-video runs asynchronously).

I guess a Lua plugin that runs this script could solve this issue, e.g.:

DEL run script-message trash-video -bnt "${path}"

Can someone provide an example how to pass mp.command_native({}) variable number of arguments to trash-video and how to process it? E.g.:

mp.command_native_async({
  name = "subprocess",
  -- args = { "trash-video" ... }, <- what to put here?
})

I want bindings like:

That would hardcode those arguments, I want to define multiple bindings with arbitrary number of arguments, e.g.:

a run script-message trash-video -bnt "${path}"
b run script-message trash-video -bn "${path}"
c run script-message trash-video -c -t "${path}"
d run script-message trash-video -d "${path}"

[avih]

This is a lua thing and not an mpv thing.

Your script-message handler does get any number of arguments which your binding send, but you need to read them correctly, e.g. like this:

mp.register_script_message("my-message", function (first, ...)
    print("first:", first)
    for i,v in ipairs(arg) do
        print(i .. ": " .. tostring(v))
    end
end)

See more info here https://www.lua.org/pil/5.2.html

[enoryw]

First argument is printed because of print("first:", first), but the rest doesn't with arg being nil:

[trash_video]
[trash_video] stack traceback:
[trash_video]         /home/enoryw/.config/mpv/scripts/trash-archive.lua:22: in function 'handler'
[trash_video]         mp.defaults:385: in function 'handler'
[trash_video]         mp.defaults:515: in function 'call_event_handlers'
[trash_video]         mp.defaults:557: in function 'dispatch_events'
[trash_video]         mp.defaults:508: in function <mp.defaults:507>
[trash_video]         [C]: at 0x5a11809e3f20
[trash_video]         [C]: at 0x5a11809e4600
[trash_video] Lua error: /home/enoryw/.config/mpv/scripts/trash-archive.lua:22: bad argument #1 to 'ipairs' (table expected, got nil)

Does (...) work with anonymous function? I"m not a programmer.

[avih]

First argument is printed because of print("first:", first), but the rest doesn't with arg being nil:

You're right, sorry. It changed between lua version and it's still supported in my version (5.1), but no longer in 5.2 or luajit.

My link was for Lua 5.0, but because it was chapter 5.2 of that book I thought it's the manual of lua 5.2, and it's not.

That's the manual of Lua 5.2: https://www.lua.org/manual/5.2/manual.html#3.4.10 and you should always refer to it when you don't know something in Lua.

Anyway, the answer is this:

mp.register_script_message("my-message", function (first, ...)
    local  the_rest = {...}
    print("first:", first)
    for i,v in ipairs(the_rest) do
        print(i .. ": " .. tostring(v))
    end
end)

And you can choose any other name too. It doesn't have to be the_rest.

[guidocella]

mp.register_script_message("trash-video", function (first, second, third)
    mp.command_native({
        name = "subprocess",
        args = { "trash-video", unpack({first, second, third})},
    })
end)