Updates to the c-ares dependency involve the following steps:

1. Downloading the source archive for the new version.

2. Unpacking the source in a temporary workspace directory.

3. Removing the `test` directory (to save disk space).

4. Copying over the existing `.gitignore`, pre-generated `config` directory and

`cares.gyp` files.

5. Replacing the existing `deps/cares` with the workspace directory.

6. Modifying the `cares.gyp` file for file additions/deletions.

7. Rebuilding the main Node.js `LICENSE`.

The `tools/update-cares.sh` script automates the update of the c-ares source

files, preserving the existing files added by Node.js.

In the following examples, `x.y.z` should match the c-ares version to update to.

e.g.

It may be necessary to update `deps/cares/cares.gyp` if any significant changes

have occurred upstream.

Run the `tools/license-builder.sh` script to rebuild the main Node.js `LICENSE`

file. This may result in no changes if c-ares' license has not changed.

If the updated `LICENSE` contains changes for other dependencies, those should

be done in a separate pull request first.

Add the rebuilt `LICENSE` if it has been updated.

Commit the changes with a message like

set -e

BASE_DIR="$( pwd )"/

DEPS_DIR="$BASE_DIR"deps/

ARES_VERSION=$1

if [ "$#" -le 0 ]; then

echo "Error: please provide an c-ares version to update to"

echo " e.g. $0 1.18.1"

exit 1

echo "Making temporary workspace"

WORKSPACE=$(mktemp -d 2> /dev/null || mktemp -d -t 'tmp')

cleanup () {

EXIT_CODE=$?

[ -d "$WORKSPACE" ] && rm -rf "$WORKSPACE"

exit $EXIT_CODE

}

trap cleanup INT TERM EXIT

ARES_REF="cares-$(echo "$ARES_VERSION" | tr . _)"

ARES_TARBALL="c-ares-$ARES_VERSION.tar.gz"

cd "$WORKSPACE"

echo "Fetching c-ares source archive"

curl -sL -o "$ARES_TARBALL" "https://github.com/c-ares/c-ares/releases/download/$ARES_REF/$ARES_TARBALL"

gzip -dc "$ARES_TARBALL" | tar xf -

rm "$ARES_TARBALL"

mv "c-ares-$ARES_VERSION" cares

echo "Removing tests"

rm -rf "$WORKSPACE/cares/test"

echo "Copying existing .gitignore, config and gyp files"

cp -R "$DEPS_DIR/cares/config" "$WORKSPACE/cares"

cp "$DEPS_DIR/cares/.gitignore" "$WORKSPACE/cares"

cp "$DEPS_DIR/cares/cares.gyp" "$WORKSPACE/cares"

echo "Replacing existing c-ares"

rm -rf "$DEPS_DIR/cares"

mv "$WORKSPACE/cares" "$DEPS_DIR/"

echo "All done!"

echo ""

echo "Please git add c-ares, commit the new version:"

echo ""

echo "$ git add -A deps/cares"

echo "$ git commit -m \"deps: update c-ares to $ARES_VERSION\""

echo ""