Add lsof 4.82

The free, open-source, Unix administrative tool lsof (for LiSt Open
Files) displays information about files open to Unix processes.

Formula/lsof.rb

@@ -0,0 +1,18 @@
+require 'formula'
+
+class Lsof <Formula
+  url 'ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/lsof.tar.bz2'
+  version '4.82'
+  md5 '5518a0c16fc937523b3d1a946cf59e5b'
+  homepage 'http://people.freebsd.org/~abe/'
+
+  def install
+    system "tar xf lsof_4.82_src.tar"
+    Dir.chdir "lsof_4.82_src" do
+      mv "00README", "../README"
+      system "./Configure -n darwin"
+      system "make"
+      bin.install "lsof"
+    end
+  end
+end