vis(1)							      General Commands Manual							    vis(1)

NAME

       vis, inv - make unprintable and non-ASCII characters in a file visible or invisible

SYNOPSIS

       file ...

       file ...

DESCRIPTION

       reads  characters  from	each file in sequence and writes them to the standard output, converting those that are not printable or not ASCII
       into a visible form.  inv performs the inverse function, reading printable characters from each file, returning them  to  non-printable	or
       non-ASCII form, if appropriate, then writing them to standard output;

       Non-printable ASCII characters are represented using C-like escape conventions:
	      backslash
	      backspace
	      escape
	      form-feed
	      new-line
	      carriage return
	      space
	      horizontal tab
	      vertical tab
	      the character whose
		      ASCII code is the 3-digit octal number n.
	      the character whose
		      ASCII code is the 2-digit hexadecimal number n.

       Non-ASCII  single-  or multi-byte characters are examined one byte at a time.  For each byte, if it can be displayed as an ASCII character,
       it is treated as if it is an ASCII character; Otherwise, it is represented in the following conventions:
	      the 8-bit character whose
		      code value is the 3-digit octal number n.
	      the 8-bit character whose
		      code value is the 2-digit hexadecimal number n.

       Space, horizontal-tab, and new-line characters can be treated as printable (and therefore passed unaltered to the output) or  non-printable
       depending  on  the  options  selected.	Backslash,  although printable, is expanded by vis, to a pair of backslashes so that when they are
       passed back through inv, they convert back to a single backslash.

       If no input file is given, or if the argument is encountered, and inv read from the standard input.

   Options
       and recognize the following options:

	      Treat new-line, space, and horizontal tab as non-printable characters.
		      expands them visibly as and rather than passing them directly to the output.  discards these characters, expecting only  the
		      printable  expansions.   New-line  characters  are  inserted  by every 16 bytes so that the output will be in a form that is
		      usable by most editors.

	      Make    and silent about non-existent files, identical input and output, and write errors.  Normally, no input file can be the  same
		      as the output file unless it is a special file.

	      Treat horizontal-tab and space characters as non-printable
		      in the same manner that treats them.

	      Cause output to be unbuffered (byte-by-byte);
		      normally, output is buffered.

	      Cause   output to be in hexadecimal form rather than the default octal form.  Either form is accepted to as input.

EXTERNAL INFLUENCES

   Environment Variables
       determines the language in which messages are displayed.

   International Code Set Support
       Single- and multi-byte character code sets are supported.

WARNINGS

       Redirecting output to an input file destroys the original data.	Therefore, command forms such as

       should be avoided unless the source file can be safely discarded.

AUTHOR

       was developed by HP.

SEE ALSO

       cat(1), echo(1), od(1).

																	    vis(1)