1RS(1)                     BSD General Commands Manual                    RS(1)
2

NAME

4     rs — reshape a data array
5

SYNOPSIS

7     rs [-CcSs[x]] [-GgKkw N] [-EeHhjmnTtyz] [rows [cols]]
8

DESCRIPTION

10     rs reads the standard input, interpreting each line as a row of blank-
11     separated entries in an array, transforms the array according to the op‐
12     tions, and writes it on the standard output.  With no arguments
13     (argc < 2) it transforms stream input into a columnar format convenient
14     for terminal viewing, i.e. if the length (in bytes!) of the first line is
15     smaller than the display width, -et is implied, -t otherwise.
16
17     The shape of the input array is deduced from the number of lines and the
18     number of columns on the first line.  If that shape is inconvenient, a
19     more useful one might be obtained by skipping some of the input with the
20     -k option.  Other options control interpretation of the input columns.
21
22     The shape of the output array is influenced by the rows and cols specifi‐
23     cations, which should be positive integers.  If only one of them is a
24     positive integer, rs computes a value for the other which will accommo‐
25     date all of the data.  When necessary, missing data are supplied in a
26     manner specified by the options and surplus data are deleted.  There are
27     options to control presentation of the output columns, including transpo‐
28     sition of the rows and columns.
29
30     The options are as follows:
31
32     -C[x]  Output columns are delimited by the single character x.
33            A missing x is taken to be ‘^I’.
34
35     -c[x]  Input columns are delimited by the single character x.
36            A missing x is taken to be ‘^I’.
37
38     -E     Consider each character of input as an array entry.
39
40     -e     Consider each line of input as an array entry.
41
42     -GN    The gutter width (inter-column space) has N percent of the maximum
43            column width added to it.
44
45     -gN    The gutter width, normally 2, is taken to be N.
46
47     -H     Like -h, but also print the length of each line.
48
49     -h     Print the shape of the input array and do nothing else.  The shape
50            is just the number of lines and the number of entries on the first
51            line.
52
53     -j     Right adjust entries within columns.
54
55     -KN    Like -k, but print the ignored lines.
56
57     -kN    Ignore the first N lines of input.
58
59     -m     Do not trim excess delimiters from the ends of the output array.
60
61     -n     On lines having fewer entries than the first line, use null en‐
62            tries to pad out the line.  Normally, missing entries are taken
63            from the next line of input.
64
65     -S[x]  Like -C, but padded strings of x are delimiters.
66
67     -s[x]  Like -c, but maximal strings of x are delimiters.
68
69     -T     Print the pure transpose of the input, ignoring any rows or cols
70            specification.
71
72     -t     Fill in the rows of the output array using the columns of the in‐
73            put array, that is, transpose the input while honoring any rows
74            and cols specifications.
75
76     -wN    The width of the display, normally 80, is taken to be the positive
77            integer N.
78
79     -y     If there are too few entries to make up the output dimensions, pad
80            the output by recycling the input from the beginning.  Normally,
81            the output is padded with blanks.
82
83     -z     Shrink column widths to fit the largest entries appearing in them.
84
85     With no arguments, rs transposes its input, and assumes one array entry
86     per input line unless the first non-ignored line is longer than the dis‐
87     play width.  Option letters which take numerical arguments interpret a
88     missing number as zero unless otherwise indicated.
89

ENVIRONMENT

91     LC_CTYPE  The character encoding locale(1).  It decides which byte se‐
92               quences form characters and what their display width is.  If
93               unset or set to "C", "POSIX" or an unsupported value, each byte
94               is treated as a character of display width 1.
95

EXAMPLES

97     rs can be used as a filter to convert the stream output of certain pro‐
98     grams (e.g., spell(1), du(1), file(1), look(1), nm(1), who(1), and wc(1))
99     into a convenient “window” format, as in
100
101           $ who | rs
102
103     This function has been incorporated into the ls(1) program, though for
104     most programs with similar output rs suffices.
105
106     To convert stream input into vector output and back again, use
107
108           $ rs 1 0 | rs 0 1
109
110     A 10 by 10 array of random numbers from 1 to 100 and its transpose can be
111     generated with
112
113           $ jot -r 100 | rs 10 10 | tee array | rs -T >tarray
114
115     In the editor vi(1), a file consisting of a multi-line vector with 9 ele‐
116     ments per line can undergo insertions and deletions, and then be neatly
117     reshaped into 9 columns with
118
119           :1,$!rs 0 9
120
121     Finally, to sort a database by the first line of each 4-line field, try
122
123           $ rs -eC 0 4 | sort | rs -c 0 1
124

SEE ALSO

126     jot(1), pr(1), sort(1), vi(1)
127

HISTORY

129     The rs utility first appeared in 4.2BSD.
130

AUTHORS

132     John A. Kunze
133

BUGS

135     Handles only two dimensional arrays.
136
137     The algorithm currently reads the whole file into memory, so files that
138     do not fit in memory will not be reshaped.
139
140     Fields cannot be defined yet on character positions.
141
142     Re-ordering of columns is not yet possible.
143
144     There are too many options.
145
146BSD                            September 4, 2020                           BSD
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