## Variável de Ambiente `PATH`

Existe uma variável de ambiente **especial** chamada **`PATH`** que é usada pelos sistemas operacionais (Linux, macOS, Windows) para encontrar programas para executar.

O valor da variável `PATH` é uma longa string composta por diretórios separados por dois pontos `:` no Linux e macOS, e por ponto e vírgula `;` no Windows.

"میان‌افزار" یک تابع است که با هر درخواست(request) قبل از پردازش توسط هر path operation (عملیات مسیر) خاص کار می‌کند. همچنین با هر پاسخ(response) قبل از بازگشت آن نیز کار می‌کند.

* هر **درخواستی (request)** که به برنامه شما می آید را می گیرد.
* سپس می تواند کاری برای آن **درخواست** انجام دهید یا هر کد مورد نیازتان را اجرا کنید.
* سپس **درخواست** را به بخش دیگری از برنامه (توسط یک path operation مشخص) برای پردازش ارسال می کند.

    private final ParserRequest parserRequest;
    private final Path cwd;
    private final Path installationDirectory;
    private final Path userHomeDirectory;
    private final Map<String, String> userProperties;
    private final Map<String, String> systemProperties;
    private final Path topDirectory;
    private final Path rootDirectory;

    private final InputStream in;
    private final OutputStream out;

Puedes definir parámetros de Cookie de la misma manera que defines parámetros de `Query` y `Path`.

## Importar `Cookie`

Primero importa `Cookie`:

{* ../../docs_src/cookie_params/tutorial001_an_py310.py hl[3]*}

## Declarar parámetros de `Cookie`

Luego declara los parámetros de cookie usando la misma estructura que con `Path` y `Query`.

# Body - Multiple Parameters

Now that we have seen how to use `Path` and `Query`, let's see more advanced uses of request body declarations.

## Mix `Path`, `Query` and body parameters

First, of course, you can mix `Path`, `Query` and request body parameter declarations freely and **FastAPI** will know what to do.

And you can also declare body parameters as optional, by setting the default to `None`:

//// tab | Python 3.10+

        (
            "/items?limit=1&q=bar&skip=1",
            200,
            {"items": [{"item_name": "Bar"}], "q": "bar"},
        ),
    ],
)
def test_get(path, expected_status, expected_response, client: TestClient):
    response = client.get(path)
    assert response.status_code == expected_status
    assert response.json() == expected_response


@needs_py310
def test_openapi_schema(client: TestClient):

                ",proximity=" + proximity + ",ttl=" + ttl +
                ",pathOffset=" + pathOffset + ",altPathOffset=" + altPathOffset +
                ",nodeOffset=" + nodeOffset + ",path=" + path + ",altPath=" + altPath +
                ",node=" + node + "]" );
        }
    }

    int pathConsumed;
    int numReferrals;
    int flags;
    Referral[] referrals;

    List<ProtwordsItem> protwordsItemList;

    public ProtwordsFile(final String id, final String path, final Date timestamp) {
        super(id, path, timestamp);
    }

    @Override
    public String getType() {
        return PROTWORDS;
    }

    @Override
    public String getPath() {
        return path;
    }

    @Override
    public synchronized OptionalEntity<ProtwordsItem> get(final long id) {

    List<StopwordsItem> stopwordsItemList;

    public StopwordsFile(final String id, final String path, final Date timestamp) {
        super(id, path, timestamp);
    }

    @Override
    public String getType() {
        return STOPWORDS;
    }

    @Override
    public String getPath() {
        return path;
    }

    @Override
    public synchronized OptionalEntity<StopwordsItem> get(final long id) {

package pluginlistener

import (
	"fmt"
	"net"
	"os"
	"path/filepath"

	"istio.io/istio/pkg/log"
)

func NewListener(path string) (net.Listener, error) {
	// Remove unix socket before use.
	if err := os.Remove(path); err != nil && !os.IsNotExist(err) {
		// Anything other than "file not found" is an error.
		return nil, fmt.Errorf("failed to remove unix://%s: %v", path, err)
	}