go install script

go_installer_latest.sh

#!/usr/bin/env bash
# Installs (or upgrades) the latest stable Go release on Linux.
set -euo pipefail

INSTALL_DIR="/usr/local"

# Detect architecture
case "$(uname -m)" in
  x86_64)  ARCH="amd64" ;;
  aarch64) ARCH="arm64" ;;
  armv7l)  ARCH="armv6l" ;;
  i386|i686) ARCH="386" ;;
  *) echo "Unsupported architecture: $(uname -m)" >&2; exit 1 ;;
esac

echo "==> Detecting latest Go version..."
LATEST=$(curl -sL 'https://go.dev/dl/?mode=json' | python3 -c 'import sys,json; print(json.load(sys.stdin)[0]["version"])')
echo "Latest Go: $LATEST"

TARBALL="${LATEST}.linux-${ARCH}.tar.gz"
URL="https://go.dev/dl/${TARBALL}"

TMPDIR=$(mktemp -d)
trap 'rm -rf "$TMPDIR"' EXIT

echo "==> Downloading $URL"
curl -sSL -o "$TMPDIR/$TARBALL" "$URL"

echo "==> Verifying checksum"
EXPECTED_SHA=$(curl -sL 'https://go.dev/dl/?mode=json&include=all' \
  | python3 -c "
import sys, json
data = json.load(sys.stdin)
for release in data:
    for f in release.get('files', []):
        if f['filename'] == '${TARBALL}':
            print(f['sha256']); sys.exit(0)
sys.exit(1)
")
ACTUAL_SHA=$(sha256sum "$TMPDIR/$TARBALL" | awk '{print $1}')
if [ "$EXPECTED_SHA" != "$ACTUAL_SHA" ]; then
  echo "Checksum mismatch! Expected $EXPECTED_SHA, got $ACTUAL_SHA" >&2
  exit 1
fi
echo "Checksum OK."

echo "==> Removing any existing Go installation at $INSTALL_DIR/go"
sudo rm -rf "$INSTALL_DIR/go"

echo "==> Extracting to $INSTALL_DIR"
sudo tar -C "$INSTALL_DIR" -xzf "$TMPDIR/$TARBALL"

# Add to PATH in every rc file that's relevant, regardless of which shell
# is currently running this script (e.g. `bash install.sh` under a zsh login shell).
PROFILE_FILES=()
[ -f "$HOME/.bashrc" ] && PROFILE_FILES+=("$HOME/.bashrc")
[ -f "$HOME/.zshrc" ] && PROFILE_FILES+=("$HOME/.zshrc")
# Fall back to creating the rc file for the user's actual login shell if neither exists yet
if [ ${#PROFILE_FILES[@]} -eq 0 ]; then
  case "${SHELL:-}" in
    */zsh) PROFILE_FILES+=("$HOME/.zshrc") ;;
    *)     PROFILE_FILES+=("$HOME/.bashrc") ;;
  esac
fi

for PROFILE_FILE in "${PROFILE_FILES[@]}"; do
  if ! grep -q "$INSTALL_DIR/go/bin" "$PROFILE_FILE" 2>/dev/null; then
    echo "==> Adding Go to PATH in $PROFILE_FILE"
    {
      echo ''
      echo '# Go'
      echo "export PATH=\$PATH:${INSTALL_DIR}/go/bin:\$HOME/go/bin"
    } >> "$PROFILE_FILE"
  fi
done
echo "Added to: ${PROFILE_FILES[*]}. Open a new terminal, or 'source' the rc file matching your shell."

export PATH="$PATH:${INSTALL_DIR}/go/bin"
echo "==> Done."
go version