diff -Naur rpm2targz-9.0.0.4g.orig/rpmoffset.c rpm2targz-9.0.0.4g/rpmoffset.c
--- rpm2targz-9.0.0.4g.orig/rpmoffset.c	2012-04-13 13:09:35.000000000 -0600
+++ rpm2targz-9.0.0.4g/rpmoffset.c	2012-04-13 13:23:42.000000000 -0600
@@ -38,6 +38,25 @@
 #define MAGIC_SIZE_MIN 3
 #define MAGIC_SIZE_MAX 6
 
+#if defined(__INTERIX) || (defined (__SVR4) && defined (__sun)) || defined(__MACH__)
+void *memmem(const void *buf, size_t buflen, const void *pattern, size_t len)
+{
+	char *bf = (char *)buf, *pt = (char *)pattern, *p = bf;
+
+	while (len <= (buflen - (p - bf))) {
+		if (NULL != (p = memchr(p, (int)(*pt), buflen - (p - bf)))) {
+			if (0 == memcmp(p, pattern, len))
+				return p;
+			else
+				++p;
+		}
+		else
+			break;
+	}
+	return NULL;
+}
+#endif
+
 int main(int argc, char *argv[])
 {
 	int show_magic = 0;