add helix installation

.config/yadm/bootstrap.d/install-helix

@@ -0,0 +1,41 @@
+#!/bin/bash
+
+set -eu
+
+APPS_DIR="${HOME}/apps"
+
+VERSION="22.05"
+INSTALL_DIR="${APPS_DIR}/helix"
+INSTALLED_VERSION=""
+
+if [[ -x "$(command -v hx)" ]] ; then
+  INSTALLED_VERSION="$(hx --version | grep -o '[0-9]\+\.[0-9]\+')"
+fi
+
+if [[ "$VERSION" != "$INSTALLED_VERSION" ]] ; then
+  echo "Helix editor version ${VERSION} already installed."
+  exit 0
+fi
+
+echo "Installing helix editor version ${VERSION}..."
+
+URL="https://github.com/helix-editor/helix/releases/download/${VERSION}/helix-${VERSION}-x86_64-linux.tar.xz"
+
+echo "Downloading from ${URL}..."
+TARGET="$(download "$URL")"
+
+if [[ -d "${INSTALL_DIR}" ]] ; then
+  echo "Removing old helix editor installation..."
+  rm -rf "${INSTALL_DIR}"
+fi
+
+echo "Unpacking file ${TARGET}..."
+mkdir -p "${APPS_DIR}"
+tar --directory="${APPS_DIR}" -xf "${TARGET}"
+
+echo "Moving unpacked directory to ${INSTALL_DIR}"
+mv "${APPS_DIR}/helix-${VERSION}-x86_64-linux" "${INSTALL_DIR}"
+
+echo "Creating link to helix editor executable..."
+mkdir -p "${HOME}/.local/bin"
+ln -s --force "${INSTALL_DIR}/hx" "${HOME}/.local/bin/"