node playback.js play doesn't work

Hi guys,
I am trying to control Volmio2(v2.041) using CLI. however, I’ve found the playback.js (in /volumio/app/plugins/system_controller/volumio_command_line_client/commands) seems not working for some commands. It just hung there by typing ‘node playback.js play’, while ‘node playback.js next’ works fine. According to the WebSockets-API-Reference, there are a couple of commands available for Basic Playback:

the following commands I’ve tested are working:
prev (not previous)

I also try the volumio (link to, it is almost the same, even the ‘prev’ doesn’t work either!
Any idea?

I think playback.js, and some documentation I can’t find now, uses “socket.emit(‘play’,’’)”, but in my experience what works is “socket.emit(‘play’)”, without the second empty argument.

Thanks Jellby!

yes, it works fine with “socket.emit(‘play’)” or “socket.emit(‘play’, null)”, but it gets hung with “socket.emit(‘play’, ‘’)”.

The document describes:

I am just wondering what the data format of the song number is. Is it the position of a song or something else?
I tried “socket.emit(‘play’, ‘3’)” or “socket.emit(‘play’, 3)”, but the same, it is freezing too…

Is it a bug there?

it is the same in the version 2.129. Well, i may change my question to: How can I start playing a song in a specific position in the command line? For example, start playing with the third song.
Any recommendation is appreciated.