diff --git a/tools/apriori/debug.c b/tools/apriori/debug.c
new file mode 100644
index 0000000..263e09f
--- /dev/null
+++ b/tools/apriori/debug.c
@@ -0,0 +1,38 @@
+#include <debug.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#define NUM_COLS  (32)
+
+int dump_hex_buffer(FILE *s, void *b, size_t len, size_t elsize) {
+    int num_nonprintable = 0;
+    int i, last;
+    char *pchr = (char *)b;
+    fputc('\n', s);
+    fprintf(s, "%p: ", b);
+    for (i = last = 0; i < len; i++) {
+        if (!elsize) {
+            if (i && !(i % 4)) fprintf(s, " ");
+            if (i && !(i % 8)) fprintf(s, " ");
+        } else {
+            if (i && !(i % elsize)) fprintf(s, " ");
+        }
+
+        if (i && !(i % NUM_COLS)) {
+            while (last < i) {
+                if (isprint(pchr[last]))
+                    fputc(pchr[last], s);
+                else {
+                    fputc('.', s); 
+                    num_nonprintable++;
+                }
+                last++;
+            }
+            fprintf(s, " (%d)\n%p: ", i, b);
+        }
+        fprintf(s, "%02x", (unsigned char)pchr[i]);
+    }
+    if (i && (i % NUM_COLS)) fputs("\n", s);
+    return num_nonprintable;
+}
+