ht: Headless Terminal

* https://lib.rs/gh/wez/wezterm/wezterm / https://crates.io/crates/termwiz

(Projects that build on this crate includes "ratatui" among others...)

In particular, I note at least these specific feature areas:

* "support functions for applications interested in either displaying data to a terminal or in building a terminal emulator": https://lib.rs/crates/termwiz

* "to help with parsing input received from a terminal": https://docs.rs/termwiz/latest/termwiz/input/index.html

* "Model a cell in the terminal display": https://docs.rs/termwiz/latest/termwiz/cell/index.html

* "parse escape sequences and attach semantic meaning": https://docs.rs/termwiz/latest/termwiz/escape/index.html

* "abstraction over a terminal device": https://docs.rs/termwiz/latest/termwiz/terminal/index.html

* https://docs.rs/termwiz/latest/termwiz/color/index.html

* "cross platform API for working with the psuedo terminal (pty) interfaces": https://lib.rs/crates/portable-pty

* "Low level escape sequence parser": https://lib.rs/crates/vtparse

So, seems like quite a lot there to help avoid re-inventing the wheel for terminal-related functionality (for andyk/ku1ik & others).

glibc compatibility breakage is the bane of my existence.

The situation is made worse by GitHub pushing people to build against the default extremely recent glibc in "ubuntu-latest" for binary artifact builds rather than what should be done: building against the oldest glibc possible (you can still do that within a "ubuntu-latest" container).

glibc breaks "version compatibility" at times for the most IMO ridiculous reasons but also has support for running binaries linked against older glibc versions on newer glibc that just gets completely ignored.

I've never seen a systemd service example for Minecraft which allowed for sending commands to the server CLI and seeing the result without involving screen/tmux/etc. The top result on Google just doesn't allow command input at all, running the service "headless", the one on the official MC wiki uses screen, and the only other options I've seen use RCON which is neither secure nor does it show the responses you'd get on the MC console.

If there's a way to run just the straight Minecraft JAR as a background service and still be able to interact with it in the occasional cases where I need to I'm very interested.

For me this looks like

-- /etc/systemd/system/minecraft.service --

  [Unit]                                    
  Description="Minecraft server service"
  
  [Service]
  Environment=JAVA_HOME="/usr/lib/jvm/java-22-openjdk"
  WorkingDirectory=/home/steam/minecraft/1.20.6/
  ExecStart=/usr/lib/jvm/java-22-openjdk/bin/java -Xmx4096M -Xms1024M -jar /home/steam/minecraft/1.20.6/server.jar nogui
  User=steam
  Group=steam

  Sockets=minecraft.socket
  StandardInput=socket
  StandardOutput=journal
  StandardError=journal

  [Install]
  WantedBy=multi-user.target

  [Socket]                                  
  ListenFIFO=%t/minecraft.stdin         
  Service=minecraft.service

What this will do is add a systemd dependency on minecraft.service to start minecraft.socket first(which creates the fifo `/run/minecraft.stdin`) then setup minecraft.service to listen to this socket for it's StandardInput(while leaving stdout and stderr pointing towards the journal).

The service can then be started and set to automatically start on boot(`systemctl daemon-reload && systemctl enable --now minecraft`). While running, data can be written to the socket file with `echo` and redirection(e.x. `echo "help" > /run/minecraft.stdin`), and the output will be visible in the journal(`journalctl -xef --unit minecraft.service`)

If you set stderr/out to go over the socket as well, then you can attach something like `screen` to it and use it like a typical TTY(or `telnet`).

This uses the file `/run/minecraft.stdin` as the socket, but the documentation for systemd.socket shows that this can also be a TCP port to listen for connections(and systemd.service shows using regular files, but then you have to manually set them up).

I built my own probably not very good equivalent of your thing called icommandlib. I'm going to investigate ripping it out and replacing it with your tool.