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VIS(1)			FreeBSD	General	Commands Manual			VIS(1)

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

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

     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
	     sequences 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-print-
	     able 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	encoded	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

     -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

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

     -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
	     encoded.  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)

     vis supports multibyte character input.  The encoding conversion is
     influenced	by the setting of the LC_CTYPE environment variable which
     defines 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 cor-
     rect locale or to the C locale.  If the locales of	the data and the con-
     version are mismatched, multibyte character recognition may fail and
     encoding will be performed	byte-by-byte instead.

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

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

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

FreeBSD	Ports 11.2	       February	19, 2013	    FreeBSD Ports 11.2


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