Added ndn_memcmp
diff --git a/ndn-cpp/c/util/ndn_memory.c b/ndn-cpp/c/util/ndn_memory.c
index d0e8bf4..12ee131 100644
--- a/ndn-cpp/c/util/ndn_memory.c
+++ b/ndn-cpp/c/util/ndn_memory.c
@@ -5,6 +5,24 @@
 
 #include "ndn_memory.h"
 
+#if !HAVE_MEMCMP
+int ndn_memcmp(unsigned char *buf1, unsigned char *buf2, unsigned int len)
+{
+  unsigned int i;
+  
+  for (i = 0; i < len; i++) {
+    if (buf1[i] > buf2[i])
+      return 1;
+    else if (buf1[i] < buf2[i])
+      return -1;
+  }
+  
+  return 0;
+}
+#else
+int ndn_memcmp_stub_to_avoid_empty_file_warning = 0;
+#endif
+
 #if !HAVE_MEMCPY
 void ndn_memcpy(unsigned char *dest, unsigned char *src, unsigned int len)
 {
@@ -27,4 +45,4 @@
 }
 #else
 int ndn_memset_stub_to_avoid_empty_file_warning = 0;
-#endif
\ No newline at end of file
+#endif