diff --git a/uidswap.h b/uidswap.h
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+/*
+
+uidswap.h
+
+Author: Tatu Ylonen <ylo@cs.hut.fi>
+
+Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+                   All rights reserved
+
+Created: Sat Sep  9 01:43:15 1995 ylo
+Last modified: Sat Sep  9 02:34:04 1995 ylo
+
+*/
+
+#ifndef UIDSWAP_H
+#define UIDSWAP_H
+
+/* Temporarily changes to the given uid.  If the effective user id is not
+   root, this does nothing.  This call cannot be nested. */
+void temporarily_use_uid(uid_t uid);
+
+/* Restores the original effective user id after temporarily_use_uid().
+   This should only be called while temporarily_use_uid is effective. */
+void restore_uid();
+
+/* Permanently sets all uids to the given uid.  This cannot be called while
+   temporarily_use_uid is effective.  This must also clear any saved uids. */
+void permanently_set_uid(uid_t uid);
+
+#endif /* UIDSWAP_H */