added SKM installer

SKM is a simple and powerful SSH Keys Manager. It helps you to manage your multiple SSH keys easily!

https://github.com/TimothyYe/skm

skm.sh

@@ -0,0 +1,104 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# ── Config ──────────────────────────────────────────────
+REPO="TimothyYe/skm"
+VERSION="${VERSION:-latest}"   # set VERSION=v0.8.7 to pin
+PREFIX="$HOME/.local/bin"      # non-sudo install path
+
+# ── Helpers ─────────────────────────────────────────────
+need() { command -v "$1" >/dev/null 2>&1 || { echo "Missing dependency: $1"; exit 1; }; }
+tmpdir() { mktemp -d 2>/dev/null || mktemp -d -t skm; }
+cleanup() { [[ -n "${WORKDIR:-}" && -d "$WORKDIR" ]] && rm -rf "$WORKDIR"; }
+trap cleanup EXIT
+
+detect_platform() {
+  local uos uarch
+  uos="$(uname -s | tr '[:upper:]' '[:lower:]')"
+  uarch="$(uname -m)"
+
+  case "$uos" in
+    linux) OS="linux" ;;
+    darwin) OS="darwin" ;;
+    *) echo "Unsupported OS: $uos"; exit 1 ;;
+  esac
+
+  case "$uarch" in
+    x86_64|amd64) ARCH="amd64" ;;
+    aarch64|arm64) ARCH="arm64" ;;
+    i386|i686) ARCH="386" ;;
+    armv7l|armv7|armv6l|armv6|armv5l|arm) ARCH="arm" ;;
+    *) echo "Unsupported architecture: $uarch"; exit 1 ;;
+  esac
+}
+
+get_latest_tag() {
+  need curl
+  curl -fsSL "https://api.github.com/repos/${REPO}/releases/latest" \
+    | grep -m1 '"tag_name":' \
+    | sed -E 's/.*"tag_name": *"([^"]+)".*/\1/'
+}
+
+build_url() {
+  local tag="$1" os="$2" arch="$3" ver="${tag#v}"
+  echo "https://github.com/${REPO}/releases/download/${tag}/skm_${ver}_${os}_${arch}.tar.gz"
+}
+
+resolve_url() {
+  local tag="$1" os="$2" arch="$3"
+  local url alt
+  url="$(build_url "$tag" "$os" "$arch")"
+  if curl -fsI "$url" >/dev/null 2>&1; then
+    echo "$url"; return 0
+  fi
+  if [[ "$os" == "linux" && "$arch" == "arm64" ]]; then
+    alt="$(build_url "$tag" "$os" "arm")"
+    if curl -fsI "$alt" >/dev/null 2>&1; then
+      echo "$alt"; return 0
+    fi
+  fi
+  echo "No release asset found for ${os}/${arch} (tag ${tag})." >&2
+  exit 1
+}
+
+# ── Main ────────────────────────────────────────────────
+echo "→ Detecting platform..."
+detect_platform
+echo "   OS=${OS} ARCH=${ARCH}"
+
+if [[ "$VERSION" == "latest" ]]; then
+  echo "→ Fetching latest SKM release..."
+  TAG="$(get_latest_tag)"
+else
+  TAG="$VERSION"
+fi
+echo "   Using release: $TAG"
+
+URL="$(resolve_url "$TAG" "$OS" "$ARCH")"
+echo "→ Downloading: $URL"
+
+WORKDIR="$(tmpdir)"
+cd "$WORKDIR"
+FILENAME="${URL##*/}"
+curl -fL --progress-bar -o "$FILENAME" "$URL"
+
+echo "→ Extracting..."
+tar -xzf "$FILENAME"
+
+BIN="$(find . -maxdepth 2 -type f -name skm | head -n1 || true)"
+[[ -n "$BIN" && -f "$BIN" ]] || { echo "Could not find skm binary"; exit 1; }
+
+mkdir -p "$PREFIX"
+mv "$BIN" "$PREFIX/skm"
+chmod +x "$PREFIX/skm"
+
+echo "→ Installed at $PREFIX/skm"
+
+# Add to PATH if not already
+if ! echo "$PATH" | grep -q "$HOME/.local/bin"; then
+  echo "⚠️  $HOME/.local/bin is not in your PATH."
+  echo "   Add this to your shell config (e.g. ~/.bashrc or ~/.zshrc):"
+  echo "   export PATH=\"\$HOME/.local/bin:\$PATH\""
+fi
+
+echo "✅ Done. Version: $($PREFIX/skm --version)"