tty
printf '%s\n' "$TERM"

man console_codes | col -b
man setterm | col -b
man vconsole.conf | col -b
man loadkeys | col -b
man keymaps | col -b
man setfont | col -b
man reset | col -b
infocmp -1 linux

---
name: linux-console
os: lnx
disable-model-invocation: true
description: "Use for Linux kernel virtual consoles (/dev/ttyN, Ctrl+Alt+F1): getty, TERM=linux, vconsole.conf, setfont, loadkeys, setterm, fbcon. Not emulators, ptys, tmux, X11, or Wayland."
---

# Linux Console

## Scope

Use for kernel virtual consoles only:

- `/dev/ttyN`
- `TERM=linux`
- `tty1`, `tty2`, ...
- `Ctrl+Alt+F1` / VT switching
- `getty`, `vconsole.conf`, `setfont`, `loadkeys`, `setterm`, `fbcon`

Do not use for:

- graphical terminal emulators
- `/dev/pts/*` pseudo-terminals
- tmux internals
- X11 / Wayland / XKB config

## First Probe

Identify the target host and VT from the user's report before probing.
The agent's stdin and `TERM` describe its execution context, not necessarily the target console.

Run these in the target session, or ask the user for their output there:

```sh
tty
printf '%s\n' "$TERM"
```

Interpret:

- Target `/dev/ttyN` + `TERM=linux` → real VT likely.
- Agent `/dev/pts/N` or `not a tty` → target remains unknown; do not reject VT diagnosis.
- Target `/dev/pts/N` → pty; clarify whether a separate VT is the actual target.
- User reports `tty1`/`tty2` on another session/host → continue target-specific read-only diagnosis.

Use `infocmp -1 linux` to inspect console capabilities; it does not detect the target.
Do not send console escape sequences to the agent's terminal as a substitute for the target.
Missing local man page → fetch current upstream man page.

## Learn Locally First

Prefer local truth over memory:

```sh
man console_codes | col -b
man setterm | col -b
man vconsole.conf | col -b
man loadkeys | col -b
man keymaps | col -b
man setfont | col -b
man reset | col -b
infocmp -1 linux
```

For deeper lookup:
`references/research.md`.

## Durable Rules

- `TERM=linux` describes Linux-console capabilities via terminfo.
- `clear` and `reset` differ; inspect `infocmp -1 linux`.
- Linux console interprets control/escape sequences; verify in
  `console_codes(4)`.
- Existing screen cells may need redraw after display/attribute changes.
- Keymap, font, palette, and persistence scopes differ; classify first.

## Change Hygiene

For every proposed change, state:

- target:
  current VT | all VTs | boot/persistent
- mechanism:
  escape seq | terminfo | kbd tool | system config | ioctl
- privilege needs:
  none | user permissions | root/admin | unknown until probed
- rollback/reset path

## Safety

- Never apply X11/Wayland/XKB/niri fixes to Linux console.
- Never confuse `/dev/ttyN` with `/dev/pts/N`.
- Do not change keymaps/fonts/persistent config without explicit user intent.
- Prefer `setterm`, `loadkeys`, `setfont`, `vconsole.conf` docs over guesses.

## References

Read when needed:

- `references/research.md` — fresh docs, command probes, web fallbacks.
- `references/model.md` — VT model, terminfo, reset/clear, screen memory.
- `references/tools.md` — setterm/loadkeys/setfont/vconsole scope notes.