adding script

Author: lemire

scripts/clang_format.sh

@@ -0,0 +1,35 @@
+#!/bin/sh
+#
+# clang formats all files in the repository.
+# certain files are excluded via .clang-format-ignore files
+# supported from clang format 18 upwards.
+
+set -eu
+
+cf=clang-format-18
+
+# Check if clang-format is installed
+if ! command -v $cf 2>&1 >/dev/null
+then
+    echo "Error: $cf not found. Please install Clang version 18."
+    echo "We recommend using the clang_format_docker.sh script."
+    exit 1
+fi
+
+if ! command -v git 2>&1 >/dev/null
+then
+    echo "Error: Git not found. Please install Git to use this script."
+    echo "You can get Git from:"
+    echo "  - Linux: Most distributions include Git; use your package manager (e.g., 'sudo apt-get install git')"
+    echo "  - macOS: Use Homebrew with 'brew install git'"
+    echo "  - Windows: Download from the official Git website"
+    exit 1
+fi
+
+gitroot="$(git rev-parse --show-toplevel)"
+
+cd "$gitroot"
+
+git ls-files -z | \
+    grep -z -E '(\.cpp|\.h)$' |\
+    xargs --null -P $(nproc) -n1 $cf -i

scripts/clang_format_docker.sh

@@ -0,0 +1,38 @@
+#!/bin/sh
+#
+# clang formats all files in the repository, using
+# a specific docker image.
+
+set -eu
+
+# Check if Docker is installed
+if ! command -v docker 2>&1 >/dev/null
+then
+    echo "Error: Docker not found. Please install Docker to use this script."
+    echo "You can get Docker from:"
+    echo "  - Linux: https://docs.docker.com/engine/install/"
+    echo "  - macOS: Use Homebrew with 'brew install --cask docker'"
+    echo "  - Windows: Download from Docker Desktop website"
+    exit 1
+fi
+
+# Check if Git is installed
+if ! command -v git 2>&1 >/dev/null
+then
+    echo "Error: Git not found. Please install Git to use this script."
+    echo "You can get Git from:"
+    echo "  - Linux: Most distributions include Git; use your package manager (e.g., 'sudo apt-get install git')"
+    echo "  - macOS: Use Homebrew with 'brew install git'"
+    echo "  - Windows: Download from the official Git website"
+    exit 1
+fi
+
+gitroot="$(git rev-parse --show-toplevel)"
+
+cd "$gitroot"
+
+docker run -v"$(pwd):/src"  \
+       --workdir /src \
+       -u "$(id -u $USER):$(id -g $USER)" \
+       ghcr.io/pauldreik/clang-format-18:latest \
+       scripts/clang_format.sh