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32 .\" @(#)vis.1 8.4 (Berkeley) 4/19/94
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40 .Nd display non-printable characters in a visual format
49 utility is a filter for converting non-printable characters
50 into a visual representation. It differs from
53 the form is unique and invertible. By default, all non-graphic
54 characters except space, tab, and newline are encoded.
55 A detailed description of the
56 various visual formats is given in
59 The options are as follows:
62 Turns off prepending of backslash before up-arrow control sequences
63 and meta characters, and disables the doubling of backslashes. This
64 produces output which is neither invertible or precise, but does
65 represent a minimum of change to the input. It is similar to
68 Request a format which displays a small subset of the
69 non-printable characters using C-style backslash sequences.
73 to fold output lines to foldwidth columns (default 80), like
76 that a hidden newline sequence is used, (which is removed
77 when inverting the file back to its original form with
79 If the last character in the encoded file does not end in a newline,
80 a hidden newline sequence is appended to the output.
82 the output usable with various editors and other utilities which
83 typically don't work with partial lines.
88 Mark newlines with the visible sequence
90 followed by the newline.
92 Turns off any encoding, except for the fact that backslashes are
93 still doubled and hidden newline sequences inserted if
97 is selected. When combined with the
102 an invertible version of the
104 utility. That is, the output
105 can be unfolded by running the output through
108 Request a format which displays non-printable characters as
109 an octal number, \eddd.
111 Only characters considered unsafe to send to a terminal are encoded.
112 This flag allows backspace, bell, and carriage return in addition
113 to the default space, tab and newline.
115 Tabs are also encoded.
117 White space (space-tab-newline) is also encoded.