diff --git a/contrib/libc-vis/unvis.3 b/contrib/libc-vis/unvis.3
index 34ebde67433b..7f219916de16 100644
--- a/contrib/libc-vis/unvis.3
+++ b/contrib/libc-vis/unvis.3
@@ -1,4 +1,4 @@
-.\"	$NetBSD: unvis.3,v 1.27 2012/12/15 07:34:36 wiz Exp $
+.\"	$NetBSD: unvis.3,v 1.29 2017/10/24 19:14:55 abhinav Exp $
 .\"	$FreeBSD$
 .\"
 .\" Copyright (c) 1989, 1991, 1993
@@ -35,7 +35,10 @@
 .Os
 .Sh NAME
 .Nm unvis ,
-.Nm strunvis
+.Nm strunvis ,
+.Nm strnunvis ,
+.Nm strunvisx ,
+.Nm strnunvisx
 .Nd decode a visual representation of characters
 .Sh LIBRARY
 .Lb libc
@@ -184,7 +187,7 @@ char out;
 
 while ((ch = getchar()) != EOF) {
 again:
-	switch(unvis(\*[Am]out, ch, \*[Am]state, 0)) {
+	switch(unvis(&out, ch, &state, 0)) {
 	case 0:
 	case UNVIS_NOCHAR:
 		break;
@@ -198,7 +201,7 @@ again:
 		errx(EXIT_FAILURE, "Bad character sequence!");
 	}
 }
-if (unvis(\*[Am]out, '\e0', \*[Am]state, UNVIS_END) == UNVIS_VALID)
+if (unvis(&out, '\e0', &state, UNVIS_END) == UNVIS_VALID)
 	(void)putchar(out);
 .Ed
 .Sh ERRORS
diff --git a/contrib/libc-vis/vis.3 b/contrib/libc-vis/vis.3
index 58e9b37999cf..35dcffea5c78 100644
--- a/contrib/libc-vis/vis.3
+++ b/contrib/libc-vis/vis.3
@@ -1,4 +1,4 @@
-.\"	$NetBSD: vis.3,v 1.45 2016/06/08 15:00:04 wiz Exp $
+.\"	$NetBSD: vis.3,v 1.49 2017/08/05 20:22:29 wiz Exp $
 .\"	$FreeBSD$
 .\"
 .\" Copyright (c) 1989, 1991, 1993
@@ -30,7 +30,7 @@
 .\"
 .\"     @(#)vis.3	8.1 (Berkeley) 6/9/93
 .\"
-.Dd January 14, 2015
+.Dd April 22, 2017
 .Dt VIS 3
 .Os
 .Sh NAME
@@ -243,6 +243,8 @@ except space, tab, and newline are encoded (see
 The following flags
 alter this:
 .Bl -tag -width VIS_WHITEX
+.It Dv VIS_DQ
+Also encode double quotes
 .It Dv VIS_GLOB
 Also encode the magic characters
 .Ql ( * ,
@@ -310,7 +312,7 @@ warning on the use of the
 .Dv VIS_NOSLASH
 flag below).
 .Pp
-There are four forms of encoding.
+There are six forms of encoding.
 All forms use the backslash character
 .Ql \e
 to introduce a special
@@ -401,6 +403,9 @@ If
 .Fa nextc
 is an octal digit, the latter representation is used to
 avoid ambiguity.
+.Pp
+Non-printable characters without C-style
+backslash sequences use the default representation.
 .It Dv VIS_OCTAL
 Use a three digit octal sequence.
 The form is
@@ -408,6 +413,11 @@ The form is
 where
 .Em d
 represents an octal digit.
+.It Dv VIS_CSTYLE \&| Dv VIS_OCTAL
+Same as
+.Dv VIS_CSTYLE
+except that non-printable characters without C-style
+backslash sequences use a three digit octal sequence.
 .It Dv VIS_HTTPSTYLE
 Use URI encoding as described in RFC 1738.
 The form is
diff --git a/contrib/libc-vis/vis.c b/contrib/libc-vis/vis.c
index aeae86c66c3d..21c07b70619d 100644
--- a/contrib/libc-vis/vis.c
+++ b/contrib/libc-vis/vis.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: vis.c,v 1.71 2016/01/14 20:41:23 christos Exp $	*/
+/*	$NetBSD: vis.c,v 1.74 2017/11/27 16:37:21 christos Exp $	*/
 
 /*-
  * Copyright (c) 1989, 1993
@@ -57,7 +57,7 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: vis.c,v 1.71 2016/01/14 20:41:23 christos Exp $");
+__RCSID("$NetBSD: vis.c,v 1.74 2017/11/27 16:37:21 christos Exp $");
 #endif /* LIBC_SCCS and not lint */
 #ifdef __FBSDID
 __FBSDID("$FreeBSD$");
@@ -379,6 +379,7 @@ makeextralist(int flags, const char *src)
 	if (flags & VIS_SP) *d++ = L' ';
 	if (flags & VIS_TAB) *d++ = L'\t';
 	if (flags & VIS_NL) *d++ = L'\n';
+	if (flags & VIS_DQ) *d++ = L'"';
 	if ((flags & VIS_NOSLASH) == 0) *d++ = L'\\';
 	*d = L'\0';
 
@@ -408,6 +409,14 @@ istrsenvisx(char **mbdstp, size_t *dlen, const char *mbsrc, size_t mblength,
 	_DIAGASSERT(mbsrc != NULL || mblength == 0);
 	_DIAGASSERT(mbextra != NULL);
 
+	mbslength = (ssize_t)mblength;
+	/*
+	 * When inputing a single character, must also read in the
+	 * next character for nextc, the look-ahead character.
+	 */
+	if (mbslength == 1)
+		mbslength++;
+
 	/*
 	 * Input (mbsrc) is a char string considered to be multibyte
 	 * characters.  The input loop will read this string pulling
@@ -424,12 +433,12 @@ istrsenvisx(char **mbdstp, size_t *dlen, const char *mbsrc, size_t mblength,
 	/* Allocate space for the wide char strings */
 	psrc = pdst = extra = NULL;
 	mdst = NULL;
-	if ((psrc = calloc(mblength + 1, sizeof(*psrc))) == NULL)
+	if ((psrc = calloc(mbslength + 1, sizeof(*psrc))) == NULL)
 		return -1;
-	if ((pdst = calloc((4 * mblength) + 1, sizeof(*pdst))) == NULL)
+	if ((pdst = calloc((16 * mbslength) + 1, sizeof(*pdst))) == NULL)
 		goto out;
 	if (*mbdstp == NULL) {
-		if ((mdst = calloc((4 * mblength) + 1, sizeof(*mdst))) == NULL)
+		if ((mdst = calloc((16 * mbslength) + 1, sizeof(*mdst))) == NULL)
 			goto out;
 		*mbdstp = mdst;
 	}
@@ -452,13 +461,6 @@ istrsenvisx(char **mbdstp, size_t *dlen, const char *mbsrc, size_t mblength,
 	 * stop at NULs because we may be processing a block of data
 	 * that includes NULs.
 	 */
-	mbslength = (ssize_t)mblength;
-	/*
-	 * When inputing a single character, must also read in the
-	 * next character for nextc, the look-ahead character.
-	 */
-	if (mbslength == 1)
-		mbslength++;
 	bzero(&mbstate, sizeof(mbstate));
 	while (mbslength > 0) {
 		/* Convert one multibyte character to wchar_t. */
@@ -470,12 +472,13 @@ istrsenvisx(char **mbdstp, size_t *dlen, const char *mbsrc, size_t mblength,
 			clen = 1;
 			cerr = 1;
 		}
-		if (clen == 0)
+		if (clen == 0) {
 			/*
 			 * NUL in input gives 0 return value. process
 			 * as single NUL byte and keep going.
 			 */
 			clen = 1;
+		}
 		/* Advance buffer character pointer. */
 		src++;
 		/* Advance input pointer by number of bytes read. */
@@ -485,6 +488,7 @@ istrsenvisx(char **mbdstp, size_t *dlen, const char *mbsrc, size_t mblength,
 	}
 	len = src - psrc;
 	src = psrc;
+
 	/*
 	 * In the single character input case, we will have actually
 	 * processed two characters, c and nextc.  Reset len back to
diff --git a/contrib/libc-vis/vis.h b/contrib/libc-vis/vis.h
index e307a39d326f..b024b8e8d2af 100644
--- a/contrib/libc-vis/vis.h
+++ b/contrib/libc-vis/vis.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: vis.h,v 1.24 2016/01/14 20:42:14 christos Exp $	*/
+/*	$NetBSD: vis.h,v 1.25 2017/04/23 01:57:36 christos Exp $	*/
 /*	$FreeBSD$	*/
 
 /*-
@@ -52,6 +52,7 @@
 #define	VIS_NL		0x0010	/* also encode newline */
 #define	VIS_WHITE	(VIS_SP | VIS_TAB | VIS_NL)
 #define	VIS_SAFE	0x0020	/* only encode "unsafe" characters */
+#define	VIS_DQ		0x8000	/* also encode double quotes */
 
 /*
  * other