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