NAME
rs —
reshape a data array
SYNOPSIS
rs |
[-CcSs
[x]]
[-GgKkw N]
[-EeHhjmnTty]
[rows
[cols]] |
DESCRIPTION
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 it transforms
stream input into a columnar format convenient for terminal viewing.
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 described below.
-
-
- -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 line of input as an array entry.
-
-
- -G
N
- The gutter width (inter-column space) has
N percent of the maximum column width added to
it.
-
-
- -g
N
- The gutter width (inter-column space), 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.
-
-
- -K
N
- Like -k, but print the ignored
lines.
-
-
- -k
N
- 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.
-
-
- -w
N
- 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
- Adapt 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.
EXAMPLES
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
who | rs
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
rs 1 0 | rs 0 1
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
:1,$!rs 0 9
Finally, to sort a database by the first line of each 4-line field, try
rs -eC 0 4 | sort | rs -c 0 1
SEE ALSO
jot(1),
pr(1),
sort(1),
vi(1)
HISTORY
The
rs utility first appeared in
4.2BSD.
AUTHORS
John A. Kunze
BUGS
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.