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VIS(1)			    General Commands Manual			VIS(1)

NAME
       vis -- display non-printable characters in a visual format

SYNOPSIS
       vis [-bcfhlmnostw] [-e extra] [-F foldwidth] [file ...]

DESCRIPTION
       vis  is	a filter for converting	non-printable characters into a	visual
       representation.	It differs from	`cat -v' in that the  form  is	unique
       and  invertible.	  By default, all non-graphic characters except	space,
       tab, and	newline	are encoded.  A	detailed description  of  the  various
       visual formats is given in vis(3).

       The options are as follows:

       -b      Turns  off  prepending of backslash before up-arrow control se-
	       quences and meta	characters, and	disables the doubling of back-
	       slashes.	 This produces output which is neither	invertible  or
	       precise,	 but  does represent a minimum of change to the	input.
	       It is similar to	"cat -v".  (VIS_NOSLASH)

       -c      Request a format	which displays a  small	 subset	 of  the  non-
	       printable   characters	using	C-style	 backslash  sequences.
	       (VIS_CSTYLE)

       -e extra
	       Also encode characters in extra,	per svis(3).

       -F foldwidth
	       Causes vis to fold output lines to foldwidth  columns  (default
	       80),  like  fold(1),  except  that a hidden newline sequence is
	       used, (which is removed when inverting the  file	 back  to  its
	       original	form with unvis(1)).  If the last character in the en-
	       coded file does not end in a newline, a hidden newline sequence
	       is  appended  to	the output.  This makes	the output usable with
	       various editors and other utilities which typically don't  work
	       with partial lines.

       -f      Same as -F.

       -h      Encode using the	URI encoding from RFC 1808.  (VIS_HTTPSTYLE)

       -l      Mark  newlines  with the	visible	sequence `\$', followed	by the
	       newline.

       -m      Encode using the	MIME Quoted-Printable encoding from RFC	 2045.
	       (VIS_MIMESTYLE)

       -n      Turns  off  any	encoding, except for the fact that backslashes
	       are still doubled and hidden newline sequences inserted	if  -f
	       or -F is	selected.  When	combined with the -f flag, vis becomes
	       like  an	 invertible  version of	the fold(1) utility.  That is,
	       the output can  be  unfolded  by	 running  the  output  through
	       unvis(1).

       -o      Request	a format which displays	non-printable characters as an
	       octal number, \ddd.  (VIS_OCTAL)

       -s      Only characters considered unsafe to send to a terminal are en-
	       coded.  This flag allows	backspace, bell, and  carriage	return
	       in addition to the default space, tab and newline.  (VIS_SAFE)

       -t      Tabs are	also encoded.  (VIS_TAB)

       -w      White space (space-tab-newline) is also encoded.	 (VIS_WHITE)

MULTIBYTE CHARACTER SUPPORT
       vis supports multibyte character	input.	The encoding conversion	is in-
       fluenced	 by the	setting	of the LC_CTYPE	environment variable which de-
       fines the set of	characters that	can be copied without encoding.

       When 8-bit data is present in the input,	LC_CTYPE must be  set  to  the
       correct	locale or to the C locale.  If the locales of the data and the
       conversion are mismatched, multibyte character recognition may fail and
       encoding	will be	performed byte-by-byte instead.

ENVIRONMENT
       LC_CTYPE	 Specify the locale of the input data.	Set to C if the	 input
		 data locale is	unknown.

SEE ALSO
       unvis(1), svis(3), vis(3)

HISTORY
       The  vis	 command  appears  in 4.4BSD.  Myltibyte character support was
       added in	NetBSD 7.0 and FreeBSD 9.2.

FreeBSD	13.0		       February	19, 2013			VIS(1)

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