diff --git a/tools/ijar/common.h b/tools/ijar/common.h
new file mode 100644
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--- /dev/null
+++ b/tools/ijar/common.h
@@ -0,0 +1,102 @@
+// Copyright 2001,2007 Alan Donovan. All rights reserved.
+//
+// Author: Alan Donovan <adonovan@google.com>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// common.h -- common definitions.
+//
+
+#ifndef INCLUDED_DEVTOOLS_IJAR_COMMON_H
+#define INCLUDED_DEVTOOLS_IJAR_COMMON_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+namespace devtools_ijar {
+
+typedef unsigned long long u8;
+typedef uint32_t u4;
+typedef uint16_t u2;
+typedef uint8_t  u1;
+
+// be = big endian, le = little endian
+
+inline u1 get_u1(const u1 *&p) {
+    return *p++;
+}
+
+inline u2 get_u2be(const u1 *&p) {
+    u4 x = (p[0] << 8) | p[1];
+    p += 2;
+    return x;
+}
+
+inline u2 get_u2le(const u1 *&p) {
+    u4 x = (p[1] << 8) | p[0];
+    p += 2;
+    return x;
+}
+
+inline u4 get_u4be(const u1 *&p) {
+    u4 x = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
+    p += 4;
+    return x;
+}
+
+inline u4 get_u4le(const u1 *&p) {
+    u4 x = (p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0];
+    p += 4;
+    return x;
+}
+
+inline void put_u1(u1 *&p, u1 x) {
+    *p++ = x;
+}
+
+inline void put_u2be(u1 *&p, u2 x) {
+    *p++ = x >> 8;
+    *p++ = x & 0xff;
+}
+
+inline void put_u2le(u1 *&p, u2 x) {
+    *p++ = x & 0xff;
+    *p++ = x >> 8;;
+}
+
+inline void put_u4be(u1 *&p, u4 x) {
+    *p++ = x >> 24;
+    *p++ = (x >> 16) & 0xff;
+    *p++ = (x >> 8) & 0xff;
+    *p++ = x & 0xff;
+}
+
+inline void put_u4le(u1 *&p, u4 x) {
+    *p++ = x & 0xff;
+    *p++ = (x >> 8) & 0xff;
+    *p++ = (x >> 16) & 0xff;
+    *p++ = x >> 24;
+}
+
+// Copy n bytes from src to p, and advance p.
+inline void put_n(u1 *&p, const u1 *src, size_t n) {
+  memcpy(p, src, n);
+  p += n;
+}
+
+extern bool verbose;
+
+}  // namespace devtools_ijar
+
+#endif // INCLUDED_DEVTOOLS_IJAR_COMMON_H