# Serial port support for ReactPHP

> [!NOTE]
> Only Linux is supported for now. Feel free to contribute support for additional platforms.

## Installing

```bash
$ composer require noccylabs/react-serial:@dev
```

## Using

The `SerialFactory` is really a *SerialStreamFactory*. Its `open()` method returns a promise
that will resolve with a duplex stream for the port.

```php
$serial = new SerialFactory();
$serial->open("/dev/ttyUSB0", 115200)
    ->then(function (DuplexStreamInterface $stream) { ... });
```

You may find that you need line buffering, in which case you should wrap the stream in a
`LineBufferedDuplexStream`. The wrapped stream will emit the same `data` and `close` events
as the original stream, but it will also emit a `line` event once a full line has been
received. If you give it a `$promptPattern` in the constructor it will also emit a `prompt`
event whenever a matching prompt is detected, and with `$bufferOutput` you will also get
an `output` event with all the `line`s emitted since the last `prompt`.

```php
// Wrap our stream and use '#> ' as the prompt pattern.
$shell = new LineBufferedDuplexStream($stream, promptPattern: '/\#\> /', bufferOutput:true);

// Prepare the commands to execute, in order. These are the commands you would use
// on an OpenWRT router to configure the WiFi password for the "main" WiFi interface.
$commands = [
    'uci set wireless.main.key="pennyisafreeloader"',
    'uci commit wireless',
    'wifi restart',
];

// Execute the next command once we get a prompt
$shell->on("prompt", function () use ($shell, &$commands) {
    $command = array_shift($commands);
    if (!$command) {
        // Closing the wrapper closes the stream
        $shell->close();
        return;
    }
    echo $command."\n";
    $shell->write($command."\n");
});

// Receives all the output lines from the last command.
$shell->on("output", function(array $lines) {
    echo "  ".join("\n  ",$lines)."\n";
});

// write "echo" to the shell on our fictive device to get a fresh prompt
$shell->write("echo\n");
```