*
     * @param key the environment variable key
     * @return the environment variable value, or null if not found
     */
    public static String getEnv(String key) {
        return System.getenv(key);
    }

    /**
     * Returns the system environment variable value for the specified key, or the default value if not found.
     *
     * @param key the environment variable key

			log.Printf("failed to ping sqlDB, got error %v", err)
			os.Exit(1)
		}

		RunMigrations()
	}
}

func OpenTestConnection(cfg *gorm.Config) (db *gorm.DB, err error) {
	dbDSN := os.Getenv("GORM_DSN")
	switch os.Getenv("GORM_DIALECT") {
	case "mysql":
		log.Println("testing mysql...")
		if dbDSN == "" {
			dbDSN = mysqlDSN
		}
		db, err = gorm.Open(mysql.Open(dbDSN), cfg)
	case "postgres":

مثلاً می‌تونی یه فایل `main.py` داشته باشی با:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

آرگومان دوم <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> مقدار پیش‌فرضیه که برمی‌گردونه.

    object : ThreadFactory {
      private var nextId = 1

      override fun newThread(runnable: Runnable): Thread = Thread(runnable, "$name-${nextId++}")
    }
}

fun getEnv(name: String) = System.getenv(name)

val SYSTEM_FILE_SYSTEM = FileSystem.SYSTEM

For example you could have a file `main.py` with:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

The second argument to <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> is the default value to return.

        }
        if (generatorList != null && !generatorList.isEmpty()) {
            String path = System.getenv("PATH");
            if (path == null) {
                path = System.getenv("Path");
            }
            if (path == null) {
                path = System.getenv("path");
            }
            final List<String> pathList = new ArrayList<>();
            pathList.add("/usr/share/fess/bin");

	c.got = append(c.got, query)
	return c.db.QueryRowContext(ctx, query, args...)
}

func TestConnPoolWrapper(t *testing.T) {
	dialect := os.Getenv("GORM_DIALECT")
	if dialect != "mysql" {
		t.SkipNow()
	}

	dbDSN := os.Getenv("GORM_DSN")
	if dbDSN == "" {
		dbDSN = "gorm:gorm@tcp(localhost:9910)/gorm?charset=utf8&parseTime=True&loc=Local"
	}
	nativeDB, err := sql.Open("mysql", dbDSN)

উদাহরণস্বরূপ, আপনার `main.py` নামে একটি ফাইল থাকতে পারেঃ

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

<a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> এর দ্বিতীয় আর্গুমেন্টটি হলো এর ডিফল্ট ভ্যালু যা রিটার্ন করা হবে।

	public class Downloader extends java.net.Authenticator
	{
	  protected java.net.PasswordAuthentication getPasswordAuthentication()
	  {
	    return new java.net.PasswordAuthentication( System.getenv( "MVNW_USERNAME" ), System.getenv( "MVNW_PASSWORD" ).toCharArray() );
	  }
	  public static void main( String[] args ) throws Exception
	  {
	    setDefault( new Downloader() );

include(":samples:static-server")
include(":samples:tlssurvey")
include(":samples:unixdomainsockets")
include(":container-tests")

project(":okhttp-logging-interceptor").name = "logging-interceptor"

val androidHome = System.getenv("ANDROID_HOME")
val localProperties = Properties().apply {
  val file = File("local.properties")
  if (file.exists()) {
    load(file.inputStream())
  }
}
val sdkDir = localProperties.getProperty("sdk.dir")