vigo · January 27, 2012 18:00 · Jan 27, 2012
diff --git a/free-memory.rb b/free-memory.rb
@@ -0,0 +1,19 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+# By Uğur Özyılmazel, @vigobronx | @ugurozyilmazel
+# http://vigodome.com | http://ugur.ozyilmazel.com | http://github.com/vigo
+
+def get_paged_memory_usage(match_string, paging=4096)
+  mvar = 3
+  if match_string.split(/[^\w]/).length > 1
+    mvar = 4
+  end
+  paged_val = `vm_stat | grep "Pages #{match_string}:" | awk '{ print $#{mvar}}'`.to_i
+  gigabyte_val = (paged_val * paging) / 1024 / 1024 / 1000.0
+end
+
+installed_memory = `sysctl -n hw.memsize`.to_i / 1024 / 1024 / 1000.0
+total_consumed = 0
+['wired down', 'active', 'inactive'].each { |key| total_consumed += get_paged_memory_usage(key) }
+printf("%.2fG", (installed_memory-total_consumed)) # returns in gigabytes