package http

import (
	"context"
	"net"
	"syscall"
	"time"
)

// CheckPortAvailability - check if given host and port is already in use.
// Note: The check method tries to listen on given port and closes it.
// It is possible to have a disconnected client in this tiny window of time.
func CheckPortAvailability(host, port string, opts TCPOptions) (err error) {
	lc := &net.ListenConfig{

  }

  override fun createSocket(
    host: String,
    port: Int,
  ): Socket = TODO("Not yet implemented")

  override fun createSocket(
    host: String,
    port: Int,
    localHost: InetAddress,
    localPort: Int,
  ): Socket = TODO("Not yet implemented")

  override fun createSocket(
    host: InetAddress,
    port: Int,
  ): Socket = TODO("Not yet implemented")

то встроенная переменная `__name__`, автоматически создаваемая Python в вашем файле, будет иметь значение строкового типа `"__main__"`.

Тогда выполнится условие и эта часть кода:

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

будет запущена.

---

Но этого не произойдет, если вы импортируете этот модуль (файл).

Таким образом, если у вас есть файл `importer.py` с таким импортом:

```Python

	"istio.io/istio/istioctl/pkg/util/proto"
	"istio.io/istio/pilot/pkg/model"
	v3 "istio.io/istio/pilot/pkg/xds/v3"
	"istio.io/istio/pkg/config/host"
)

// ClusterFilter is used to pass filter information into cluster based config writer print functions
type ClusterFilter struct {
	FQDN      host.Name
	Port      int
	Subset    string
	Direction model.TrafficDirection
}

// Verify returns true if the passed cluster matches the filter fields

			}
			if port < 1 || port > 65535 {
				logger.Fatal(fmt.Errorf("invalid arguments passed to --ftp=%s, (port number must be between 1 to 65535)", arg), "unable to start FTP server")
			}
			publicIP = host
		case "passive-port-range":
			portRange = tokens[1]
		case "tls-private-key":
			tlsPrivateKey = tokens[1]
		case "tls-public-cert":
			tlsPublicCert = tokens[1]
		}
	}

labels.search_result_sort_filename_desc=File Name (descending)
labels.search_result_similar=Similar Results ({0})
labels.facet_timestamp_3month=Past 3 Months
labels.facet_timestamp_6month=Past 6 Months
labels.facet_timestamp_2year=Past 2 Years
labels.facet_timestamp_3year=Past 3 Years
labels.facet_contentLength_10kto50k=10kb - 50kb
labels.facet_contentLength_50kto100k=50kb - 100kb
labels.facet_contentLength_100kto250k=100kb - 250kb

        else -> ""
      }
    val effectiveHost =
      when {
        url.host.contains(":") -> "[" + url.host + "]"
        else -> url.host
      }
    assertThat(url.scheme, "scheme").isEqualTo(testData.scheme)
    assertThat(effectiveHost, "host").isEqualTo(testData.host)
    assertThat(effectivePort, "port").isEqualTo(testData.port)
    assertThat(url.encodedPath, "path").isEqualTo(testData.path)

      socketHost = address.url.host
      socketPort = address.url.port
    } else {
      val proxyAddress = proxy.address()
      require(proxyAddress is InetSocketAddress) {
        "Proxy.address() is not an InetSocketAddress: ${proxyAddress.javaClass}"
      }
      socketHost = proxyAddress.socketHost
      socketPort = proxyAddress.port
    }

    if (socketPort !in 1..65535) {

	// within all pods as we do on the host.
	//
	// This should be fine, as the host binaries are all we have to work with here anyway,
	// as we are running within a privileged container - and we don't want to take the time to
	// redetect for each pod anyway.
	//
	// Extreme corner case:
	// If for some reason your host had both binaries, and you were injecting out-of-band

따라서 섹션

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

이 실행됩니다.

---

해당 모듈(파일)을 가져오면 이런 일이 발생하지 않습니다

그래서 다음과 같은 다른 파일 `importer.py`가 있는 경우:

```Python
from myapp import app

# Some more code
```

이 경우 `myapp.py` 내부의 자동 변수에는 값이 `"__main__"`인 변수 `__name__`이 없습니다.

따라서 다음 행

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

은 실행되지 않습니다.