Add download-release.sh for easy install

I wanted an easy way to get llama-server on my machine.

I figured this would be useful for other people as well.

Take a look at the docstring and help text, it should be fairly intuitive.

Tested as working on a mac m1. The path handling only works with unixy paths for now, sorry windows people.
If you want, this is ripe for improving in this regard.

I tried to keep portability in mind besides that though, though I'm no shell expert.

scripts/download-release.sh

@@ -0,0 +1,201 @@
+#!/bin/bash
+
+# Downloads a release from the llama.cpp repository.
+#
+# Example usage:
+#   curl -s https://raw.githubusercontent.com/ggerganov/llama.cpp/master/download-release.sh | bash -s -- /path/to/dest --tag=latest
+#   chmod +x /path/to/dest/llama-server
+#   /path/to/dest/llama-server --help
+#
+# list of release zips available as of release b3190 (2024-06-20):
+# cudart-llama-bin-win-cu11.7.1-x64.zip
+# cudart-llama-bin-win-cu12.2.0-x64.zip
+# llama-b3190-bin-macos-arm64.zip
+# llama-b3190-bin-macos-x64.zip
+# llama-b3190-bin-ubuntu-x64.zip
+# llama-b3190-bin-win-avx-x64.zip
+# llama-b3190-bin-win-avx2-x64.zip
+# llama-b3190-bin-win-avx512-x64.zip
+# llama-b3190-bin-win-cuda-cu11.7.1-x64.zip
+# llama-b3190-bin-win-cuda-cu12.2.0-x64.zip
+# llama-b3190-bin-win-kompute-x64.zip
+# llama-b3190-bin-win-llvm-arm64.zip
+# llama-b3190-bin-win-msvc-arm64.zip
+# llama-b3190-bin-win-noavx-x64.zip
+# llama-b3190-bin-win-openblas-x64.zip
+# llama-b3190-bin-win-rpc-x64.zip
+# llama-b3190-bin-win-sycl-x64.zip
+# llama-b3190-bin-win-vulkan-x64.zip
+
+parse_args() {
+    if [ "$#" -lt 1 ]; then
+        print_help
+        exit 1
+    fi
+    DEST_DIR="$1"
+    shift
+    for i in "$@"; do
+        case $i in
+        --help)
+            print_help
+            exit 0
+            ;;
+        --dest=*)
+            DEST_DIR="${i#*=}"
+            shift
+            ;;
+        --tag=*)
+            TAG="${i#*=}"
+            shift
+            ;;
+        --filename=*)
+            FILENAME="${i#*=}"
+            shift
+            ;;
+        --os=*)
+            OS="${i#*=}"
+            shift
+            ;;
+        --arch=*)
+            ARCH="${i#*=}"
+            shift
+            ;;
+        --backend=*)
+            BACKEND="${i#*=}"
+            shift
+            ;;
+        *)
+            print_help
+            exit 1
+            ;;
+        esac
+    done
+    # if not set, default to latest
+    TAG=${TAG:-latest}
+    BACKEND=${BACKEND:-cuda-cu12.2.0}
+    get_tag
+    get_os
+    get_arch
+    get_filename
+}
+
+print_help() {
+    echo "Usage: download-llama-cpp.sh --help"
+    echo "       download-llama-cpp.sh <dest> --tag=<tag> --filename=<filename> --os=<os> --arch=<arch> --backend=<backend>"
+    echo "Options:"
+    echo "  <dest>                   Destination directory to download the files to."
+    echo "                           e.g. the llama-server executable will be at <dest>/llama-server"
+    echo "  --tag=<tag>              Release tag to download. Default: latest"
+    echo "  --filename=<filename>    Filename to download. If supplied, will"
+    echo "                           override the os/arch/backend options."
+    echo "                           If not supplied,"
+    echo "                           will be constructed from the os/arch/backend options."
+    echo "  --os=<os>                OS to download for. Default: auto-detected"
+    echo "  --arch=<arch>            Architecture to download for. Default: auto-detected"
+    echo "  --backend=<backend>      Backend to download for. Only relevant for Windows. Default: cuda-cu12.2.0"
+}
+
+get_tag() {
+    # if not latest, return
+    if [ "$TAG" != "latest" ]; then
+        return
+    fi
+    # extract the tag from the latest release:
+    # "tag_name": "v1.0.0",
+    # Trying to avoid needing jq or a real json parser
+    TAG=$(
+        curl -s "https://api.github.com/repos/ggerganov/llama.cpp/releases/latest" |
+            # there can be a variable amount of whitespace between the key and value
+            sed -n 's/.*"tag_name":[ \n]*"\([^"]*\)".*/\1/p'
+    )
+    echo "Latest release tag found to be: $TAG"
+}
+
+get_os() {
+    # if already set, return
+    if [ -n "$OS" ]; then
+        return
+    fi
+    OS=$(uname -s)
+
+    case "$OS" in
+    Linux)
+        OS="ubuntu"
+        ;;
+    Darwin)
+        OS="macos"
+        ;;
+    CYGWIN* | MINGW32* | MSYS* | MINGW*)
+        OS="win"
+        ;;
+    *)
+        echo "Unsupported OS: $OS"
+        exit 1
+        ;;
+    esac
+}
+
+get_arch() {
+    # if already set, return
+    if [ -n "$ARCH" ]; then
+        return
+    fi
+    ARCH=$(uname -m)
+
+    case "$ARCH" in
+    x86_64)
+        ARCH="x64"
+        ;;
+    arm64)
+        ARCH="arm64"
+        ;;
+    *)
+        echo "Unsupported architecture: $ARCH"
+        exit 1
+        ;;
+    esac
+}
+
+get_filename() {
+    if [ -n "$FILENAME" ]; then
+        return
+    fi
+    if [[ "$OS" == "ubuntu" ]]; then
+        FILENAME="llama-$TAG-bin-ubuntu-$ARCH.zip"
+    elif [[ "$OS" == "macos" ]]; then
+        FILENAME="llama-$TAG-bin-macos-$ARCH.zip"
+    elif [[ "$OS" == "win" ]]; then
+        FILENAME="llama-$TAG-bin-win-$BACKEND-$ARCH.zip"
+    fi
+}
+
+ensure_downloaded() {
+    # only download if the file does not exist
+    if [ -f "$ZIP_PATH" ]; then
+        echo "File $ZIP_PATH already exists, skipping download"
+        return
+    fi
+    local base_url="https://github.com/ggerganov/llama.cpp/releases/download"
+    URL="$base_url/$TAG/$FILENAME"
+    echo "Downloading $URL to $ZIP_PATH"
+    curl -L -o "$ZIP_PATH" "$URL"
+}
+
+main() {
+    parse_args "$@"
+
+    mkdir -p "$DEST_DIR"
+    ZIP_PATH="$DEST_DIR/$FILENAME"
+    ensure_downloaded
+
+    echo "Unzipping $ZIP_PATH to $DEST_DIR"
+    unzip "$ZIP_PATH" -d "$DEST_DIR"
+    # All of the contents are in a build/bin subdirectory,
+    # move all of the contents up to the DEST_DIR
+    mv "$DEST_DIR/build/bin"/* "$DEST_DIR"
+    rmdir "$DEST_DIR/build/bin" "$DEST_DIR/build"
+
+    echo "Done!"
+}
+
+main "$@"