Call Magento2 REST API from command line without curl

rest.php

<?php
use Magento\Framework\App\Bootstrap;
use Magento\Framework\App\ErrorHandler;
use Magento\Framework\App\Http;
use Magento\Framework\App\Request\Http as RequestHttp;
use Magento\Framework\Webapi\Rest\Request;
use \Magento\Framework\Webapi\Rest\Response;
use Zend\Http\Header\ContentType;

require 'app/bootstrap.php';
$handler = new ErrorHandler();
set_error_handler([$handler, 'handler']);
echo "[";
register_shutdown_function(function () { echo "\n]"; });

function send(Response $response) {
    static $isFirst = true;
    $isError = !$response->isSuccess() || $response->isException();
    if (!$isError && !$GLOBALS["curl_return_result"]) {
        return;
    }
    if (!$isFirst) {
        echo ",";
    }
    $isFirst = false;
    echo "\n";
    $response->sendResponse();

    if ($isError && !$GLOBALS["curl_continue_on_errors"]) {
        exit(1);
    }
}

function curl($path, $method, $payload) {

    $bootstrap = Bootstrap::create(BP, []);
    $om = $bootstrap->getObjectManager();
    $om->configure([
        'preferences' => [
            'Magento\Framework\Authorization\PolicyInterface' => 'Magento\Framework\Authorization\Policy\DefaultPolicy'
        ]
    ]);
    $app = $bootstrap->createApplication(Http::class);

    /** @var Request $restRequest */
    $restRequest = $om->get(Request::class);
    $restRequest->getHeaders()->addHeader(new ContentType("application/json"));
    $restRequest->setMethod($method);
    $restRequest->setContent($payload);

    /** @var RequestHttp $request */
    $request = $om->get(RequestHttp::class);
    $request->setPathInfo($path);

    $response = $app->launch();

    if ($response instanceof Response) {
        send($response);
    } else {
        echo "{\"message\": \"Unexpected response type: " . get_class($response) . " - wrong path?\"}";
        exit(1);
    }
}

$GLOBALS["curl_return_result"] = false;
$GLOBALS["curl_continue_on_errors"] = false;

curl("/rest/all/V1/products/FULL_PRODUCT_MODEL", "PUT", <<<PAYLOAD
{"product":{"sku":"FULL_PRODUCT_MODEL","status":0,"extension_attributes":{"stock_item":{"use_config_backorders":1}}}}
PAYLOAD
);
curl("/all/V1/products/FULL_INCLOMPLETE_PRODUCT", "PUT", <<<PAYLOAD
{"product":{"sku":"FULL_INCLOMPLETE_PRODUCT","status":1,"visibility":1,"extension_attributes":{"stock_item":{"qty":43,"backorders":0,"use_config_backorders":0,"is_in_stock":true}}}}
PAYLOAD
);
curl("/all/V1/products/FULL_SIMPLE_PRODUCT", "PUT", <<<PAYLOAD
{"product":{"sku":"FULL_SIMPLE_PRODUCT","visibility":4,"extension_attributes":{"stock_item":{"qty":1,"backorders":1,"use_config_backorders":0,"is_in_stock":true}}}}
PAYLOAD
);
curl("/all/V1/products/MINIMAL_PRODUCT", "PUT", <<<PAYLOAD
{"product":{"sku":"MINIMAL_PRODUCT","visibility":2,"extension_attributes":{"stock_item":{"backorders":1,"use_config_backorders":0}}}}
PAYLOAD
);