|RS(1)||General Commands Manual||RS(1)|
rsreads 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
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:
-h, but also print the length of each line.
-k, but print the ignored lines.
-C, but padded strings of x are delimiters.
-c, but maximal strings of x are delimiters.
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
rscan 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
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
rsutility first appeared in 4.2BSD.
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.
|October 24, 2016||OpenBSD-current|