rs —
reshape a
data array
rs |
[-CcSs[x]]
[-GgKkw
N]
[-EeHhjmnTtyz]
[rows
[cols]] |
rs reads the standard input, interpreting each line
as a row of blank-separated entries in an array, transforms the array
according to the options, and writes it on the standard output. With no
arguments
(
argc
< 2
)
it transforms stream input into a columnar format convenient for terminal
viewing, i.e. if the length (in bytes!) of the first line is smaller than the
display width,
-et is implied,
-t otherwise.
The shape of the input array is deduced from the number of lines and the number
of columns on the first line. If that shape is inconvenient, a more useful one
might be obtained by skipping some of the input with the
-k option. Other options control interpretation
of the input columns.
The shape of the output array is influenced by the
rows and
cols specifications, which should be positive
integers. If only one of them is a positive integer,
rs computes a value for the other which will
accommodate all of the data. When necessary, missing data are supplied in a
manner specified by the options and surplus data are deleted. There are
options to control presentation of the output columns, including transposition
of the rows and columns.
The options are as follows:
-
-C[x]
- Output columns are delimited by the single character
x.
A missing x is taken to be
‘^I
’.
-
-c[x]
- Input columns are delimited by the single character
x.
A missing x is taken to be
‘^I
’.
- -E
- Consider each character of input as an array entry.
- -e
- Consider each line of input as an array entry.
-
-GN
- The gutter width (inter-column space) has
N percent of the maximum column width
added to it.
-
-gN
- The gutter width, normally 2, is taken to be
N.
- -H
- Like -h, but also print the
length of each line.
- -h
- Print the shape of the input array and do nothing else. The
shape is just the number of lines and the number of entries on the first
line.
- -j
- Right adjust entries within columns.
-
-KN
- Like -k, but print the ignored
lines.
-
-kN
- Ignore the first N lines
of input.
- -m
- Do not trim excess delimiters from the ends of the output
array.
- -n
- On lines having fewer entries than the first line, use null
entries to pad out the line. Normally, missing entries are taken from the
next line of input.
-
-S[x]
- Like -C, but padded strings of
x are delimiters.
-
-s[x]
- Like -c, but maximal strings
of x are delimiters.
- -T
- Print the pure transpose of the input, ignoring any
rows or
cols specification.
- -t
- Fill in the rows of the output array using the columns of
the input array, that is, transpose the input while honoring any
rows and
cols specifications.
-
-wN
- The width of the display, normally 80, is taken to be the
positive integer N.
- -y
- If there are too few entries to make up the output
dimensions, pad the output by recycling the input from the beginning.
Normally, the output is padded with blanks.
- -z
- Shrink column widths to fit the largest entries appearing
in them.
With no arguments,
rs transposes its input, and
assumes one array entry per input line unless the first non-ignored line is
longer than the display width. Option letters which take numerical arguments
interpret a missing number as zero unless otherwise indicated.
LC_CTYPE
- The character encoding
locale(1). It decides which byte sequences
form characters and what their display width is. If unset or set to
“
C
”,
“POSIX
” or an unsupported value,
each byte is treated as a character of display width 1.
rs can be used as a filter to convert the stream
output of certain programs (e.g.,
spell(1),
du(1),
file(1),
look(1),
nm(1),
who(1), and
wc(1))
into a convenient “window” format, as in
This function has been incorporated into the
ls(1)
program, though for most programs with similar output
rs suffices.
To convert stream input into vector output and back again, use
A 10 by 10 array of random numbers from 1 to 100 and its transpose can be
generated with
$ jot -r 100 | rs 10 10 | tee array | rs -T >tarray
In the editor
vi(1), a file consisting of a
multi-line vector with 9 elements per line can undergo insertions and
deletions, and then be neatly reshaped into 9 columns with
Finally, to sort a database by the first line of each 4-line field, try
$ rs -eC 0 4 | sort | rs -c 0 1
jot(1),
pr(1),
sort(1),
vi(1)
The
rs utility first appeared in
4.2BSD.
John A. Kunze
Handles only two dimensional arrays.
The algorithm currently reads the whole file into memory, so files that do not
fit in memory will not be reshaped.
Fields cannot be defined yet on character positions.
Re-ordering of columns is not yet possible.
There are too many options.