# nerves_motd

[![Hex version](https://img.shields.io/hexpm/v/nerves_motd.svg "Hex version")](https://hex.pm/packages/nerves_motd)
[![API docs](https://img.shields.io/hexpm/v/nerves_motd.svg?label=hexdocs "API docs")](https://hexdocs.pm/nerves_motd/NervesMOTD.html)
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`nerves_motd` prints a ["message of the
day"](https://en.wikipedia.org/wiki/Motd_(Unix)) on Nerves devices.

![](https://user-images.githubusercontent.com/7563926/202566900-942f3963-ff0e-48c2-9e13-03f96dd9a0d0.png)

## Usage

The primary function is `NervesMOTD.print()` which prints the base layout based
on the template below:

```
<LOGO>
<APP_NAME> <APP_VERSION> (<FW_UUID>) <PLATFORM> <TARGET>
  Serial       : <SERIAL_NUMBER>
  Uptime       : 18.296 seconds
  Clock        : 2023-05-18 00:05:20 JST <synchronization state>

  Firmware     : <VALIDITY> (<A|B>)      Applications : <N> started (<not started applications>)
  Memory usage : 74 MB (15%)             Part usage   : 210 MB (14%)
  Hostname     : <HOSTNAME>              Load average : 0.05 0.14 0.15

  <IFNAME>     : <IPV6>, <IPV4>
  <EXTRA_ROWS>
```

To have `NervesMOTD` print automatically when first accessing a device, add
`NervesMOTD.print()` to your `iex.exs` file (typically in
`rootfs_overlay/etc/iex.exs`)

### Customization

`NervesMOTD.print/1` supports a few options for customizing the base layout:

* `:logo` - Change the logo displayed. Defaults to the Nerves logo. Set to `""`
  to prevent any logo from being displayed
* `:extra_rows` - a list of custom rows or a callback for returning rows to be
  appended to the end of the layout. The callback can be a 0-arity function
  reference or MFArgs tuple.

For convenience, `NervesMOTD.print/1` options may be stored in the application
environment in your `config.exs` to be used whenever `NervesMOTD.print/0` is
called:

```elixir
config :nerves_motd,
  logo: """
  Custom logo
  """,
  extra_rows: [
    [{"Label", "value"}, {"Label2", "value2"}],
    [{"Long label", "Lots of text"}]
  ]
```

## Installation

Install by adding `:nerves_motd` to your list of dependencies in `mix.exs`:

```elixir
def deps do
  [
    {:nerves_motd, "~> 0.1.0"}
  ]
end
```

You can also install it using [Igniter](https://hexdocs.pm/igniter/) with `mix igniter.install nerves_motd`.

For details, see [API reference](https://hexdocs.pm/nerves_motd/api-reference.html).

## License

All original source code in this project is licensed under Apache-2.0.

Additionally, this project follows the [REUSE recommendations](https://reuse.software)
and labels so that licensing and copyright are clear at the file level.