#!/usr/bin/env bash## This script installs an up-to-date version of CMake.## For MacOS use Homebrew to install the latest version.## For Ubuntu use the official KitWare Apt repository with backports.# See: https://apt.kitware.com/## For other systems (RHEL 8.x, 9.x, AmazonLinux, SUSE, Fedora, Arch, etc)# use the official CMake installer script from KitWare.## Note this is similar to how GitHub Actions runners install cmake:# https://github.com/actions/runner-images/blob/main/images/ubuntu/scripts/build/install-cmake.sh## Upstream:  3.30.4 (2024-09-27) set -euo pipefail  if [[ "$(uname -s)" == "darwin" ]]; then  brew --version >/dev/null \    || echo "Error: Homebrew is required to install cmake on MacOS." && exit 1  echo "Installing cmake via Homebrew (can't pin to old versions)."  brew install cmake  exit 0elif [ "$(uname -s)" != "Linux" ]; then  echo "Error: This script is intended for MacOS/Linux systems only."  exit 1elif [ -z "${1:-}" ]; then  echo "Usage: $0 [3.30.4]"  exit 1fiCMAKE_VERSION="${CMAKE_VERSION:-${1:-3.30.4}}" if [ "$(whoami)" = root ]; then SUDO=; else SUDO="$(command -v sudo || command -v doas || true)"; fi if cmake --version 2>/dev/null | grep -q "$CMAKE_VERSION"; then  echo "CMake $CMAKE_VERSION is already installed."  exit 0elif [ -e /usr/local/bin/cmake ]; then  echo "Warning: existing cmake found at /usr/local/bin/cmake. Skipping installation."  exit 0elif [ -e /etc/apt/sources.list.d/kitware.list ]; then  echo "Warning: existing KitWare repository found. Skipping installation."  exit 0elif [ -e /etc/lsb-release ] && grep -qP 'DISTRIB_ID=Ubuntu' /etc/lsb-release; then  curl -fsSL https://apt.kitware.com/keys/kitware-archive-latest.asc \    | $SUDO gpg --dearmor - \    | $SUDO tee /usr/share/keyrings/kitware-archive-keyring.gpg >/dev/null  echo "deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ $(lsb_release -cs) main" \    | $SUDO tee /etc/apt/sources.list.d/kitware.list >/dev/null  $SUDO apt-get update  $SUDO apt-get install -y kitware-archive-keyring cmakeelse  arch="$(uname -m)"  if [ "$arch" != "x86_64" ] && [ "$arch" != "aarch64" ]; then    echo "Error. Only x86_64 and aarch64 are supported."    exit 1  fi  tempdir=$(mktemp -d)  pushd "$tempdir"    CMAKE_REPO="https://github.com/Kitware/CMake"    CMAKE_INSTALLER="cmake-$CMAKE_VERSION-linux-$arch.sh"    curl -fsSL --output cmake-$CMAKE_VERSION-SHA-256.txt \      "$CMAKE_REPO/releases/download/v$CMAKE_VERSION/cmake-$CMAKE_VERSION-SHA-256.txt"    curl -fsSL --output $CMAKE_INSTALLER \      "$CMAKE_REPO/releases/download/v$CMAKE_VERSION/cmake-$CMAKE_VERSION-linux-$arch.sh"    # workaround for old versions of sha256sum not having --ignore-missing    grep -F "cmake-$CMAKE_VERSION-linux-$arch.sh" "cmake-$CMAKE_VERSION-SHA-256.txt" \      | sha256sum -c \      | grep -qP "^${CMAKE_INSTALLER}: OK"    chmod +x cmake-$CMAKE_VERSION-linux-$arch.sh    $SUDO ./cmake-$CMAKE_VERSION-linux-$arch.sh --prefix=/usr/local --skip-license  popd  rm -rf "$tempdir"fi