+++
title = "Shell"
description = "The firmware's own commands, typed on the device: look at its state, the SD card, the radio and the network with no PC and no cable."
weight = 9
[extra]
tag = "Shell"
+++
The firmware has a set of **commands**, made for working on it from a PC. The Shell runs them **on the device itself**: no computer, no cable, no Wi-Fi. It is the tool for the day something is wrong and you are nowhere near a desk.
It can do real damage: `rm` deletes, `reboot` restarts, `debug on` opens the device to the network. It is the same trust as holding the device, and nothing more.
## Using it
Type a command and press Enter. `help` lists them all; the [command reference](/dev/debug/commands/) says what each does. A few to start with:
| Command | Shows |
|---|---|
| `info` | The firmware's version, uptime, memory, Wi-Fi, the SD card and both firmware slots |
| `wifi status` | The network, the address, and where the DNS and time servers came from |
| `ls /notes` | A folder of the SD card, with sizes and dates |
| `crash` | The last crash, if there was one |
| `update check` | Whether a newer release exists |
| `lora status` | What the radio is set to and what it has heard |
- Tab **completes** what you are typing: the command, word by word (`lora st` gives `lora status`, and `gnss track ` with Tab lists `start stop`), then **a path on the SD card**. `ls /no` and Tab gives `ls /notes/`; Tab again goes on inside the folder. If several names fit, it completes as far as they agree and lists them. You can type the name in any case, and after a file command you can leave out the first slash: `cat no` and Tab gives `cat /notes/`. A name with a space in it isn't completed.
- Fn with up and down brings back **lines you typed before**.
- Alt with up and down **scrolls back** through what was printed.
- `clear` empties the screen, and `quit` (or Back) leaves.
## What you see
**The replies to your own commands, and nothing else.** The firmware prints a lot besides: IRC connecting, a packet received, whatever a PC on the USB port or the Debug Console is asking for. None of that reaches the Shell. The firmware knows who each line is printed for, so an answer that comes a moment later from another part of it (a folder listing, `tasks`) is still yours.
Ctrl + b shows **everything** the firmware prints instead, and `all` shows in the corner. Press it again to go back.
## Opening an App
Type an App's name **with a capital letter** to open it, without going back to the Launcher:
`Irc` `Wifi` `Gnss` `Gemini` `Lora` `Storage` `Notes` `System` `Settings`
The capital is the difference: every command is in small letters, every App starts with a capital. Tab completes them too.
## Deleting
`rm` works as it does on Unix, with one addition: it asks.
| You type | What happens |
|---|---|
| `rm /notes/a.txt` | Asks, then deletes the file |
| `rm -f /notes/a.txt` | Deletes it without asking |
| `rm /captures/old` | Refused: it is a folder, and a folder needs `-r` |
| `rm -r /captures/old` | Removed at once if it is empty. If not, asks first |
| `rm -rf /captures/old` | Removed with everything in it, without asking |
## Several files at once
`*` stands for any run of characters in a name and `?` for exactly one, in `ls`, `du`, `rm`, `cp` and `mv`:
| You type | What happens |
|---|---|
| `ls /notes/*.txt` | Only the notes ending in `.txt` |
| `du /captures/lora/*.pcap` | The size of each capture |
| `cp /gnss/2026-10-0?.gpx /backup` | Copies the tracks of the 1st to the 9th into `/backup`, which must exist |
| `rm /screenshots/2026*` | Asks **once**, saying how many match, then deletes them |
| `rm -f /screenshots/*` | Deletes them all without asking |
The pattern goes in the **last part** of the path (`/notes/*.txt`, not `/*/a.txt`), and capitals don't matter. A folder that matches is left alone by `rm` unless you add `-r`. At most 64 names at a time: past that nothing is done, and you are asked for a narrower pattern. `cancel` stops what is left.
The folders the firmware keeps its own files in can't be removed, as in the [Storage App](/guide/storage/).
## Screenshots
```
screenshot the screen, now
screenshot 5 the screen in 5 seconds: time to go to another App
```
The picture is saved as a PNG in `/screenshots` on the SD card, named by date and time, and a Toast says so once it is written (so the Toast is never in the picture). From the Shell, "now" is always a picture of the Shell: use the pause to get to the screen you want, or, simpler, press Fn + p on that screen: it takes the same picture from anywhere. The [Storage App](/guide/storage/) lists the files and [shows them](/guide/storage/#pictures).
## What it costs
Nothing while it is closed. Open, about 7 KB of memory, given back when you leave: with IRC connected and a Gemini page open, that can be the difference (see [the memory limit](/howto/not-enough-memory/)).
## The keys, as the device lists them
What Fn + h shows on this screen. This table is generated from the firmware's own lists, so it is always the current one.
{{ keys(scopes=["shell"]) }}