# Termianl Emulators

I used to spend a lot of time on terminal emulators, to make them match my taste, 
but now I found that it's not worth it, **Zellij can provide a user-friendly and unified user experience for all terminal emulators! without any pain**!

Currently, I only use the most basic features of terminal emulators, such as true color, graphics protocol, etc.
Other features such as tabs, scrollback buffer, select/search/copy, etc, are all provided by zellij!

My current terminal emulators are:

1. kitty: My main terminal emulator.
    1. to select/copy a large mount of text, We should do some tricks via kitty's `scrollback_pager` with neovim, it's really painful: <https://github.com/kovidgoyal/kitty/issues/719>
2. wezterm: My secondary terminal emulator.
    1. its search ability is very basic, and it's not easy to use.
    1. its scrollback buffer's copy mode is very like vim, which is nice, but zellij's even better, it can use neovim as its default scrollback buffer's editor without any pain!
3. foot: a fast, lightweight and minimalistic Wayland terminal emulator.
    1. foot only do the things a terminal emulator should do, no more, no less.
    1. It's really suitable for tiling window manager or zellij users!

## 'xterm-kitty': unknown terminal type when `ssh` into a remote host or `sudo xxx`

> https://sw.kovidgoyal.net/kitty/faq/#i-get-errors-about-the-terminal-being-unknown-or-opening-the-terminal-failing-or-functional-keys-like-arrow-keys-don-t-work

> https://wezfurlong.org/wezterm/config/lua/config/term.html

kitty set `TERM` to `xterm-kitty` by default, and TUI apps like `viu`, `yazi`, `curses` will try to search in the host's [terminfo(terminal capability data base)](https://linux.die.net/man/5/terminfo) for value of `TERM` to determine the capabilities of the terminal.

But when you `ssh` into a remote host, the remote host is very likely to not have `xterm-kitty` in its terminfo, so you will get this error:

```
'xterm-kitty': unknown terminal type
```

Or when you `sudo xxx`, `sudo` won't preserve the `TERM` variable, it will be reset to root's default `TERM` value, which is `xterm` or `xterm-256color` in most linux distributions, so you will get this error:

```
'xterm-256color': unknown terminal type
```

or 

```
Error opening terminal: xterm-kitty.
```

NixOS preserve the `TERMINFO` and `TERMINFO_DIRS` environment variables, for `root` and the `wheel` group: [nixpkgs/nixos/modules/config/terminfo.nix](https://github.com/NixOS/nixpkgs/blob/nixos-23.11/nixos/modules/config/terminfo.nix#L18)

For nix-darwin, take a look at <https://github.com/LnL7/nix-darwin/wiki/Terminfo-issues>

### Solutions

Simplest solution, it will automatically copy over the terminfo files and also magically enable shell integration on the remote machine: 

```
kitten ssh user@host
```

Or if you do not care about kitty's features(such as true color & graphics protocol), you can simply set `TERM` to `xterm-256color`, which is built-in in most linux distributions:

```
export TERM=xterm-256color
```

If you need kitty's features, but do not like the magic of `kitten`, you can manually install kitty's terminfo on the remote host:

```bash
# install on ubuntu / debian
sudo apt-get install kitty-terminfo

# or copy from local machine
infocmp -a xterm-kitty | ssh myserver tic -x -o \~/.terminfo /dev/stdin
```

