Add homebrew formula file

Author: csjayp

homebrew/subcalc.rb

@@ -0,0 +1,18 @@
+#
+# Formula for the subcalc tool
+#
+class Subcalc < Formula
+  desc "Subnet calculation and discovery tool"
+  homepage "https://github.com/csjayp/subcalc"
+  url "https://github.com/csjayp/subcalc/archive/v1.2.tar.gz"
+  sha256 "7bc926b22aa75749e1ab5878932887bc1811115703aac646c04c55f39b2809a8"
+
+  def install
+    system "make"
+    system "make", "PREFIX=#{prefix}", "install"
+  end
+
+  test do
+    system "#{bin}/subcalc", "inet", "127.0.0.1/24"
+  end
+end