Add install script with one-liner for Linux, macOS, FreeBSD, OpenBSD, Windows

Author: chiefMarlin

README.md

@@ -10,7 +10,11 @@ file signing and encryption. SSH signing uses FIDO2 ed25519-sk keys
 
 ## Install
 
-Download a binary from [Releases](../../releases), or build from source:
+```
+curl -fsSL https://raw.githubusercontent.com/8ff/sear/main/install.sh | sudo sh
+```
+
+Or download a binary from [Releases](../../releases), or build from source:
 
 ```
 go build -o sear .

install.sh

@@ -0,0 +1,43 @@
+#!/bin/sh
+set -eu
+
+REPO="8ff/sear"
+INSTALL_DIR="${INSTALL_DIR:-/usr/local/bin}"
+
+OS="$(uname -s | tr '[:upper:]' '[:lower:]')"
+ARCH="$(uname -m)"
+
+case "$ARCH" in
+    x86_64|amd64) ARCH="amd64" ;;
+    aarch64|arm64) ARCH="arm64" ;;
+    i386|i686) ARCH="386" ;;
+    *) printf "Unsupported architecture: %s\n" "$ARCH" >&2; exit 1 ;;
+esac
+
+case "$OS" in
+    linux|darwin|freebsd|openbsd) ;;
+    mingw*|msys*|cygwin*) OS="windows" ;;
+    *) printf "Unsupported OS: %s\n" "$OS" >&2; exit 1 ;;
+esac
+
+EXT=""
+if [ "$OS" = "windows" ]; then EXT=".exe"; fi
+BINARY="sear-${OS}-${ARCH}${EXT}"
+
+VERSION="$(curl -fsSL "https://api.github.com/repos/${REPO}/releases/latest" | grep '"tag_name"' | cut -d'"' -f4)"
+if [ -z "$VERSION" ]; then
+    printf "Failed to fetch latest version\n" >&2
+    exit 1
+fi
+
+URL="https://github.com/${REPO}/releases/download/${VERSION}/${BINARY}"
+printf "Installing sear %s (%s/%s) to %s\n" "$VERSION" "$OS" "$ARCH" "$INSTALL_DIR"
+
+TMP="$(mktemp)"
+trap 'rm -f "$TMP"' EXIT
+
+curl -fsSL -o "$TMP" "$URL"
+chmod +x "$TMP"
+mv "$TMP" "${INSTALL_DIR}/sear${EXT}"
+
+printf "Done: sear %s\n" "$("${INSTALL_DIR}/sear${EXT}" version 2>/dev/null || echo "$VERSION")"