--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compat/vis.h	Wed Apr 01 14:57:57 2015 +0200
@@ -0,0 +1,87 @@
+/*	$OpenBSD: vis.h,v 1.15 2015/07/20 01:52:27 millert Exp $	*/
+/*	$NetBSD: vis.h,v 1.4 1994/10/26 00:56:41 cgd Exp $	*/
+
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)vis.h	5.9 (Berkeley) 4/3/91
+ */
+
+#ifndef _VIS_H_
+#define	_VIS_H_
+
+#include <sys/types.h>
+
+/*
+ * to select alternate encoding format
+ */
+#define	VIS_OCTAL	0x01	/* use octal \ddd format */
+#define	VIS_CSTYLE	0x02	/* use \[nrft0..] where appropriate */
+
+/*
+ * to alter set of characters encoded (default is to encode all
+ * non-graphic except space, tab, and newline).
+ */
+#define	VIS_SP		0x04	/* also encode space */
+#define	VIS_TAB		0x08	/* also encode tab */
+#define	VIS_NL		0x10	/* also encode newline */
+#define	VIS_WHITE	(VIS_SP | VIS_TAB | VIS_NL)
+#define	VIS_SAFE	0x20	/* only encode "unsafe" characters */
+#define	VIS_DQ		0x200	/* backslash-escape double quotes */
+#define	VIS_ALL		0x400	/* encode all characters */
+
+/*
+ * other
+ */
+#define	VIS_NOSLASH	0x40	/* inhibit printing '\' */
+#define	VIS_GLOB	0x100	/* encode glob(3) magics and '#' */
+
+/*
+ * unvis return codes
+ */
+#define	UNVIS_VALID	 1	/* character valid */
+#define	UNVIS_VALIDPUSH	 2	/* character valid, push back passed char */
+#define	UNVIS_NOCHAR	 3	/* valid sequence, no character produced */
+#define	UNVIS_SYNBAD	-1	/* unrecognized escape sequence */
+#define	UNVIS_ERROR	-2	/* decoder in unknown state (unrecoverable) */
+
+/*
+ * unvis flags
+ */
+#define	UNVIS_END	1	/* no more characters */
+
+char	*vis(char *, int, int, int);
+int	strvis(char *, const char *, int);
+int	stravis(char **, const char *, int);
+int	strnvis(char *, const char *, size_t, int);
+int	strvisx(char *, const char *, size_t, int);
+int	strunvis(char *, const char *);
+int	unvis(char *, char, int *, int);
+ssize_t strnunvis(char *, const char *, size_t);
+
+#endif /* !_VIS_H_ */