Basic install script for Zig tarballs, that symlinks ~/.local/bin/zig-<version> to the downloaded and extracted zig binary.

install-zig.sh

#!/usr/bin/env bash

set -euo pipefail

# ----------------------------
# Check arguments
# ----------------------------
if [ "$#" -ne 1 ]; then
    echo "Usage: $0 <zig-version>"
    echo "Example: $0 0.15.2"
    exit 1
fi

VERSION="$1"

# ----------------------------
# Check if version symlink already exists
# ----------------------------

BIN_DIR="$HOME/.local/bin"
VERSION_SYMLINK="$BIN_DIR/zig-$VERSION"

if [ -e "$VERSION_SYMLINK" ]; then
    echo "Zig version $VERSION is already installed (symlink exists):"
    echo "  $VERSION_SYMLINK"
    echo "Aborting."
    exit 1
fi

# ----------------------------
# Check dependencies
# ----------------------------
for cmd in curl jq; do
    if ! command -v "$cmd" >/dev/null 2>&1; then
        echo "Error: '$cmd' is not installed."
        echo "Please install it, e.g.: sudo apt install $cmd or brew install $cmd"
        exit 1
    fi
done

# ----------------------------
# Detect OS
# ----------------------------
UNAME_S="$(uname -s)"
case "$UNAME_S" in
    Linux)
        OS="linux"
        ;;
    Darwin)
        OS="macos"
        ;;
    *)
        echo "Unsupported operating system: $UNAME_S"
        exit 1
        ;;
esac

# ----------------------------
# Detect architecture
# ----------------------------
UNAME_M="$(uname -m)"
case "$UNAME_M" in
    x86_64)
        ARCH="x86_64"
        ;;
    aarch64|arm64)
        ARCH="aarch64"
        ;;
    armv7l|armv6l)
        ARCH="arm"
        ;;
    *)
        echo "Unsupported architecture: $UNAME_M"
        exit 1
        ;;
esac

TARGET="${ARCH}-${OS}"

echo "Detected platform: $TARGET"
echo "Requested Zig version: $VERSION"

# ----------------------------
# Download index.json
# ----------------------------
INDEX_JSON="$(mktemp)"
curl -fsSL https://ziglang.org/download/index.json -o "$INDEX_JSON"

# ----------------------------
# Extract tarball URL
# ----------------------------
TARBALL_URL="$(jq -r --arg ver "$VERSION" --arg target "$TARGET" \
    '.[$ver][$target].tarball // empty' "$INDEX_JSON")"

if [ -z "$TARBALL_URL" ]; then
    echo "Could not find tarball for version '$VERSION' and target '$TARGET'"
    exit 1
fi

echo "Download URL: $TARBALL_URL"

# ----------------------------
# Download tarball
# ----------------------------

DOWNLOAD_DIR="$HOME/Downloads"
mkdir -p "$DOWNLOAD_DIR"

FILENAME="$(basename "$TARBALL_URL")"
DOWNLOAD_PATH="$DOWNLOAD_DIR/$FILENAME"

if [ -f "$DOWNLOAD_PATH" ]; then
    echo "Tarball already exists, skipping download:"
    echo "  $DOWNLOAD_PATH"
else
    echo "Downloading to $DOWNLOAD_PATH ..."
    curl -fL "$TARBALL_URL" -o "$DOWNLOAD_PATH"
    echo "Downloaded: $DOWNLOAD_PATH"
fi

# ----------------------------
# Extraction
# ----------------------------

INSTALL_DIR="$HOME/.local/zig"
EXTRACTED_DIR="${FILENAME%.tar.xz}"   # strip .tar.xz
TARGET_DIR="$INSTALL_DIR/$EXTRACTED_DIR"

mkdir -p "$INSTALL_DIR"

if [ -d "$TARGET_DIR" ]; then
    echo "Zig already appears to be installed at:"
    echo "  $TARGET_DIR"
    echo "Aborting extraction."
    exit 1
fi

echo "Extracting $FILENAME to $INSTALL_DIR ..."
tar -xf "$DOWNLOAD_PATH" -C "$INSTALL_DIR"

echo "Zig unpacked to:"
echo "  $TARGET_DIR"

# ----------------------------
# Symlink
# ----------------------------

SYMLINK="$BIN_DIR/zig-$VERSION"
ZIG_BINARY="$TARGET_DIR/zig"

mkdir -p "$BIN_DIR"

if [ ! -f "$ZIG_BINARY" ]; then
    echo "Error: Zig binary not found at:"
    echo "  $ZIG_BINARY"
    exit 1
fi

if [ -e "$SYMLINK" ]; then
    echo "Symlink already exists:"
    echo "  $SYMLINK"
    echo "Not overwriting."
    exit 1
fi

ln -s "$ZIG_BINARY" "$SYMLINK"

echo "Created symlink:"
echo "  $SYMLINK -> $ZIG_BINARY"

echo "Done."