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31 .\" @(#)col.1 8.1 (Berkeley) 6/29/93
39 .Nd filter reverse line feeds from input
47 utility filters out reverse (and half reverse) line feeds so that the output is
48 in the correct order with only forward and half forward line
49 feeds, and replaces white-space characters with tabs where possible.
50 This can be useful in processing the output of
57 utility reads from the standard input and writes to the standard output.
59 The options are as follows:
60 .Bl -tag -width indent
62 Do not output any backspaces, printing only the last character
63 written to each column position.
65 Forward half line feeds are permitted (``fine'' mode).
66 Normally characters printed on a half line boundary are printed
67 on the following line.
69 Do not output multiple spaces instead of tabs (default).
74 By default, 128 lines are buffered.
76 Force unknown control sequences to be passed through unchanged.
79 will filter out any control sequences from the input other than those
80 recognized and interpreted by itself, which are listed below.
82 Output multiple spaces instead of tabs.
85 The control sequences for carriage motion that
87 understands and their decimal values are listed in the following
90 .Bl -tag -width "carriage return" -compact
92 reverse line feed (escape then 7)
94 half reverse line feed (escape then 8)
96 half forward line feed (escape then 9)
98 moves back one column (8); ignored in the first column
102 forward line feed (10); also does carriage return
104 shift to normal character set (15)
106 shift to alternate character set (14)
108 moves forward one column (32)
110 moves forward to next tab stop (9)
112 reverse line feed (11)
115 All unrecognized control characters and escape sequences are
120 utility keeps track of the character set as characters are read and makes
121 sure the character set is correct when they are output.
123 If the input attempts to back up to the last flushed line,
125 will display a warning message.
131 environment variables affect the execution of