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;
    }

    val body = body("")
    val bytes = body.byteStream()
    assertThat(bytes.read()).isEqualTo(-1)
  }

  @Test
  fun byteStreamSeesBom() {
    val body = body("efbbbf68656c6c6f")
    val bytes = body.byteStream()
    assertThat(bytes.read()).isEqualTo(0xef)
    assertThat(bytes.read()).isEqualTo(0xbb)
    assertThat(bytes.read()).isEqualTo(0xbf)

  private val countingSource: CountingSource = CountingSource(source)
  private val source: BufferedSource = countingSource.buffer()

  /** Total bytes read thus far. */
  private val byteCount: Long
    get() = countingSource.bytesRead - source.buffer.size

  /** How many bytes to read before [peekHeader] should return false, or -1L for no limit. */
  private var limit = -1L

    // 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")

        }

        // Fill the receive buffer without holding any locks.
        val read = source.read(receiveBuffer, remainingByteCount)
        if (read == -1L) throw EOFException()
        remainingByteCount -= read

        // Move the received data to the read buffer to the reader can read it. If this source has
        // been closed since this read began we must discard the incoming data and tell the
        // connection we've done so.

def test_read_items():
    access_token = get_access_token(scope="me items")
    response = client.get(
        "/users/me/items/", headers={"Authorization": f"Bearer {access_token}"}
    )
    assert response.status_code == 200, response.text
    assert response.json() == [{"item_id": "Foo", "owner": "johndoe"}]


def test_read_system_status():
    access_token = get_access_token()

      }

      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
    }

var errChunkTooBig = errors.New("chunk too big: choose chunk size <= 16MiB")

// newSignV4ChunkedReader returns a new s3ChunkedReader that translates the data read from r
// out of HTTP "chunked" format before returning it.
// The s3ChunkedReader returns io.EOF when the final 0-length chunk is read.
//
// NewChunkedReader is not needed by normal applications. The http package
// automatically decodes chunking when reading response bodies.

    val derReader = DerReader(buffer)

    derReader.read("test") { header ->
      assertThat(header.tag).isEqualTo(16L)

      derReader.read("test") { header2 ->
        assertThat(header2.tag).isEqualTo(21L)
        assertThat(derReader.readOctetString()).isEqualTo("Smith".encodeUtf8())
      }

      derReader.read("test") { header3 ->
        assertThat(header3.tag).isEqualTo(1L)

    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]);