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32 .\" @(#)vis.1 8.4 (Berkeley) 4/19/94
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.
54 the form is unique and invertible.
55 By default, all non-graphic
56 characters except space, tab, and newline are encoded.
57 A detailed description of the
58 various visual formats is given in
61 The options are as follows:
64 Turns off prepending of backslash before up-arrow control sequences
65 and meta characters, and disables the doubling of backslashes.
67 produces output which is neither invertible or precise, but does
68 represent a minimum of change to the input.
72 Request a format which displays a small subset of the
73 non-printable characters using C-style backslash sequences.
77 to fold output lines to foldwidth columns (default 80), like
80 that a hidden newline sequence is used, (which is removed
81 when inverting the file back to its original form with
83 If the last character in the encoded file does not end in a newline,
84 a hidden newline sequence is appended to the output.
86 the output usable with various editors and other utilities which
87 typically do not work with partial lines.
92 Mark newlines with the visible sequence
94 followed by the newline.
96 Turns off any encoding, except for the fact that backslashes are
97 still doubled and hidden newline sequences inserted if
102 When combined with the
107 an invertible version of the
111 can be unfolded by running the output through
114 Request a format which displays non-printable characters as
115 an octal number, \eddd.
117 Only characters considered unsafe to send to a terminal are encoded.
118 This flag allows backspace, bell, and carriage return in addition
119 to the default space, tab and newline.
121 Tabs are also encoded.
123 White space (space-tab-newline) is also encoded.
134 Due to limitations in the underlying
139 does not recognize multibyte characters, and thus may consider them to be
140 non-printable when they are in fact printable (and vice versa).