fi
  # Enter the output directory.
  mkdir -p "$(dirname "$2")"
  pushd "$(dirname "$2")"

  # Download and make the binary executable
  echo "Downloading ztunnel: $1 to $2"
  time ${DOWNLOAD_COMMAND} --header "${AUTH_HEADER:-}" "$1" > "$2"
  chmod +x "$2"

  # Make a copy named just "ztunnel" in the same directory (overwrite if necessary).
  echo "Copying $2 to $(dirname "$2")/${3}"
  cp -f "$2" "$(dirname "$2")/${3}"
  popd

# license that can be found in the LICENSE file.

SOURCE="${BASH_SOURCE[0]}"
while [ -h "$SOURCE" ]; do
	DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
	SOURCE="$(readlink "$SOURCE")"
	[[ $SOURCE != /* ]] && SOURCE="$DIR/$SOURCE"
done
DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"

# Increase the V8 stack size from the default of 984K
# to 8192K to ensure all tests can pass without hitting
# stack size limits.

func isDirEmpty(dirname string, legacy bool) bool {
	if legacy {
		// On filesystems such as btrfs, nfs this is not true, so fallback
		// to performing readdir() instead.
		entries, err := readDirN(dirname, 1)
		if err != nil {
			return false
		}
		return len(entries) == 0
	}
	var stat syscall.Stat_t
	if err := syscall.Stat(dirname, &stat); err != nil {
		return false
	}

#   $2: The full path of the output binary.
#   $3: Non-versioned name to use
function download_envoy_if_necessary () {
  if [[ ! -f "$2" ]] ; then
    # Enter the output directory.
    mkdir -p "$(dirname "$2")"
    pushd "$(dirname "$2")"

    # Download and extract the binary to the output directory.
    echo "Downloading ${SIDECAR}: $1 to $2"
    time ${DOWNLOAD_COMMAND} --header "${AUTH_HEADER:-}" "$1" |\

package cmd

// isDirEmpty - returns true if there is no error and no object and prefix inside this directory
func isDirEmpty(dirname string, _ bool) bool {
	entries, err := readDirN(dirname, 1)
	if err != nil {
		return false
	}
	return len(entries) == 0

# Note: the normal way we use in other scripts in Istio do not work when `source`d, which is why we use this approach
SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
REPO_ROOT="$(dirname "$(dirname "${SCRIPT_DIR}")")"

LOCAL_ARCH=$(uname -m)

# Pass environment set target architecture to build system
if [[ ${TARGET_ARCH} ]]; then
    # Target explicitly set
    :

# See the License for the specific language governing permissions and
# limitations under the License.

set -exo pipefail

UPDATE_BRANCH=${UPDATE_BRANCH:-"master"}

SCRIPTPATH="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
ROOTDIR=$(dirname "${SCRIPTPATH}")
cd "${ROOTDIR}"

# Get the sha of top commit
# $1 = repo
function getSha() {
  git ls-remote "https://github.com/istio/${1}.git" "refs/heads/${UPDATE_BRANCH}" | cut -f 1
}

# the __path__ so that "from tensorflow.foo import bar" works.
# We're using bitwise, but there's nothing special about that.
_API_MODULE = _sys.modules[__name__].bitwise
_tf_api_dir = _os.path.dirname(_os.path.dirname(_API_MODULE.__file__))
_current_module = _sys.modules[__name__]

if not hasattr(_current_module, "__path__"):
  __path__ = [_tf_api_dir]
elif _tf_api_dir not in __path__:
  __path__.append(_tf_api_dir)

while [ -h "$PRG" ] ; do
  ls=`ls -ld "$PRG"`
  link=`expr "$ls" : '.*-> \(.*\)$'`
  if expr "$link" : '/.*' > /dev/null; then
    PRG="$link"
  else
    PRG="`dirname "$PRG"`/$link"
  fi
done

saveddir=`pwd`

MAVEN_HOME=`dirname "$PRG"`/..

# make it fully qualified
MAVEN_HOME=`cd "$MAVEN_HOME" && pwd`

cd "$saveddir"

CLASSWORLDS_CONF="$MAVEN_HOME/bin/m2.conf"

    if [ ! "$(expr "$readLink" : '\([^ ]*\)')" = "no" ]; then
      if $darwin; then
        javaHome="$(dirname "$javaExecutable")"
        javaExecutable="$(cd "$javaHome" && pwd -P)/javac"
      else
        javaExecutable="$(readlink -f "$javaExecutable")"
      fi
      javaHome="$(dirname "$javaExecutable")"
      javaHome=$(expr "$javaHome" : '\(.*\)/bin')
      JAVA_HOME="$javaHome"
      export JAVA_HOME