+/* for PATH_MAX */
+#ifdef HAVE_LIMITS_H
+#include <limits.h>
+#endif
+/* for MAXPATHLEN */
+#ifdef HAVE_SYS_PARAM_H
+#include <sys/param.h>
+#endif
+#ifdef PATH_MAX
+# define LD_PATHMAX PATH_MAX
+#else
+# ifdef MAXPATHLEN
+# define LD_PATHMAX MAXPATHLEN
+# else
+# define LD_PATHMAX 1024
+# endif
+#endif
+
+#ifdef HAVE_REALPATH
+# define REALPATH(a,b) realpath (a, b)
+#else
+# define REALPATH(a,b) NULL
+#endif
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+