rs - 20181225-1 main

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.
Numerous options control input, reshaping and output processing;
the simplest usage example is "ls -1 | rs", which outputs the
same (on an 80-column terminal) as the modern "ls" with no "-1"
argument.