## 建立和使用環境變數

你在 **shell（終端機）**中就可以**建立**和使用環境變數，並不需要用到 Python：

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// 你可以使用以下指令建立一個名為 MY_NAME 的環境變數
$ export MY_NAME="Wade Wilson"

// 然後，你可以在其他程式中使用它，例如
$ echo "Hello $MY_NAME"

Hello Wade Wilson
```

</div>

////

//// tab | Windows PowerShell

<div class="termy">

```console

W wielu przypadkach możesz już znać odpowiedź na te pytania. 🤓

Jeśli pomożesz wielu ludziom, możesz zostać oficjalnym [Ekspertem FastAPI](fastapi-people.md#fastapi-experts){.internal-link target=_blank}. 🎉

		t.Fatalf("expects 1 relations, but got %v", len(userSchema.Relationships.Relations))
	}

	if createdByRel, ok := userSchema.Relationships.Relations["CreatedBy"]; ok {
		if createdByRel.FieldSchema != userSchema {
			t.Fatalf("expects same field schema, but got new %p, old %p", createdByRel.FieldSchema, userSchema)
		}
	} else {
		t.Fatalf("expects created by relations, but not found")
	}
}

		return ErrRequestNotReadyYet
	}

	if UTCNow().Sub(pSignValues.Date) > pSignValues.Expires {
		return ErrExpiredPresignRequest
	}

	// Save the date and expires.
	t := pSignValues.Date
	expireSeconds := int(pSignValues.Expires / time.Second)

	// Construct new query.
	query := make(url.Values)
	clntHashedPayload := req.Form.Get(xhttp.AmzContentSha256)

     * for finalName directly in the plugin configuration section. It is also useful to ensure that - for example - a
     * List-typed parameter which expects items of type Artifact doesn't get a List full of Strings.
     *
     * @return <code>true</code> if the user should not be allowed to configure the parameter directly
     */
    boolean readonly() default false;

		}

		for _, name := range []string{"Name", "Constraint"} {
			if reflect.ValueOf(result).FieldByName(name).Interface() != reflect.ValueOf(v).FieldByName(name).Interface() {
				t.Errorf(
					"check %v %v should equal, expects %v, got %v",
					k, name, reflect.ValueOf(result).FieldByName(name).Interface(), reflect.ValueOf(v).FieldByName(name).Interface(),
				)
			}
		}
	}
}

func TestParseUniqueConstraints(t *testing.T) {

        ByteBuffer bb2 = ByteBuffer.wrap(bytes, 8, 8).order(java.nio.ByteOrder.BIG_ENDIAN);
        long data4 = bb2.getLong();

        // Construct UUID from components - Java UUID expects big-endian representation
        long mostSig = ((long) data1 << 32) | ((long) (data2 & 0xFFFF) << 16) | (data3 & 0xFFFF);
        long leastSig = data4;

        this.guid = new UUID(mostSig, leastSig);
    }

//// tab | লিনাক্স, ম্যাকওএস, উইন্ডোজ Bash

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```console
// আপনি চাইলে MY_NAME নামে একটি env var তৈরি করতে পারেন
$ export MY_NAME="Wade Wilson"

// তারপরে এটিকে চাইলে অন্যান্য প্রোগ্রামে ব্যবহার করতে পারেন
$ echo "Hello $MY_NAME"

Hello Wade Wilson
```

</div>

////

//// tab | উইন্ডোজ পাওয়ারশেল

Puedes **crear** y usar variables de entorno en la **shell (terminal)**, sin necesidad de Python:

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// Podrías crear una env var MY_NAME con
$ export MY_NAME="Wade Wilson"

// Luego podrías usarla con otros programas, como
$ echo "Hello $MY_NAME"

Hello Wade Wilson
```

</div>

////

//// tab | Windows PowerShell

<div class="termy">

```

### Things to know

- Fields such as `version` and `pools` are mandatory, however all other fields are optional.
- Each pool expects a minimum of 2 nodes per pool, and unique non-repeating hosts for each argument.
- Each pool expects each host in this pool has the same number of drives specified as any other host.