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VIS(1)			  BSD General Commands Manual			VIS(1)

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

     vis [-cbflnostw] [-F foldwidth] [file ...]

     The vis utility 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 vari-
     ous 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".

     -c	     Request a format which displays a small subset of the non-print-
	     able characters using C-style backslash sequences.

     -F	     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 do not	work with partial

     -f	     Same as -F.

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

     -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.

     -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.

     -t	     Tabs are also encoded.

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

     unvis(1), vis(3)

     The vis command appeared in 4.4BSD.

     Due to limitations	in the underlying vis(3) function, the vis utility
     does not recognize	multibyte characters, and thus may consider them to be
     non-printable when	they are in fact printable (and	vice versa).

BSD				 June 25, 2004				   BSD


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