assertTrue(source.wasStreamOpened());
    assertFalse(source.wasStreamClosed());

    StringWriter writer = new StringWriter();
    char[] buf = new char[64];
    int read;
    while ((read = reader.read(buf)) != -1) {
      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertTrue(source.wasStreamClosed());
    assertEquals(STRING, writer.toString());
  }

    assertThat(inputStream!!.read()).isEqualTo('A'.code)
    assertThat(inputStream.read()).isEqualTo('B'.code)
    assertThat(inputStream.read()).isEqualTo('C'.code)
    assertThat(inputStream.read()).isEqualTo('D'.code)
    assertThat(inputStream.read()).isEqualTo('E'.code)
    assertThat(inputStream.read()).isEqualTo('F'.code)
    assertThat(inputStream.read()).isEqualTo(-1)

  std::vector<char> out;

  // First read.
  EXPECT_TRUE(cache.ValidateAndUpdateFileSignature(filename, 123));
  TF_EXPECT_OK(ReadCache(&cache, filename, 0, 16, &out));
  EXPECT_EQ(calls, 1);

  // Second read. Hit cache.
  EXPECT_TRUE(cache.ValidateAndUpdateFileSignature(filename, 123));
  TF_EXPECT_OK(ReadCache(&cache, filename, 0, 16, &out));
  EXPECT_EQ(calls, 1);

  // Third read. File signatures are different.

    // Use it with other programs, like
    $ echo "Hello $Env:MY_NAME"

    Hello Wade Wilson
    ```

    </div>

### Read env vars in Python

You could also create environment variables outside of Python, in the terminal (or with any other method), and then read them in Python.

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

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")

      int off = (int) expectedSize - remaining;
      int read = in.read(bytes, off, remaining);
      if (read == -1) {
        // end of stream before reading expectedSize bytes
        // just return the bytes read so far
        return Arrays.copyOf(bytes, off);
      }
      remaining -= read;
    }

    // bytes is now full
    int b = in.read();
    if (b == -1) {
      return bytes;
    }

                                TF_WRITABLE_FILE_OPS_ABI, "writable file"));

  if (ops->read_only_memory_region_ops != nullptr)
    TF_RETURN_IF_ERROR(CheckABI(ops->read_only_memory_region_ops_abi,
                                TF_READ_ONLY_MEMORY_REGION_OPS_ABI,
                                "read only memory region"));

  return OkStatus();
}

      }

      val read = super.read(sink, minOf(byteCount, bytesRemainingInChunk))
      if (read == -1L) {
        carrier.noNewExchanges() // The server didn't supply the promised chunk length.
        val e = ProtocolException("unexpected end of stream")
        responseBodyComplete()
        throw e
      }
      bytesRemainingInChunk -= read
      return read
    }

    TF_SetStatus(status, TF_UNKNOWN, "Could not get content-length header");
    return -1;
  }
  // `TF_OUT_OF_RANGE` isn't considered as an error. So we clear it here.
  TF_SetStatus(status, TF_OK, "");
  TF_VLog(1, "Successful read of %s @ %u of size: %u", path.c_str(), offset,
          read);
  stream.read(buffer, read);
  read = stream.gcount();
  if (read < buffer_size) {

    assertEquals(2, lin.available());
    int read = lin.read();
    assertEquals(big[0], read);
    assertEquals(1, lin.available());
    read = lin.read();
    assertEquals(big[1], read);
    assertEquals(0, lin.available());
    read = lin.read();
    assertEquals(-1, read);

    lin.reset();
    byte[] small = new byte[5];
    read = lin.read(small);
    assertEquals(2, read);
    assertEquals(big[0], small[0]);

@needs_py39
def test_read_system_status(client: TestClient):
    access_token = get_access_token(client=client)
    response = client.get(
        "/status/", headers={"Authorization": f"Bearer {access_token}"}
    )
    assert response.status_code == 200, response.text
    assert response.json() == {"status": "ok"}


@needs_py39
def test_read_system_status_no_token(client: TestClient):