x77686d

=begin

It seems that Ruby 2.2.4, string[n] = "x" is not O(1).  It was suggested that
this was due to UTF-8 encoding, but I see the same performance with US-ASCII.

Any ideas?

$ ruby --version
ruby 2.2.4p230 (2015-12-16 revision 53155) [x86_64-linux]
$ time ruby -E US-ASCII:US-ASCII storeseq2.rb 1000 1000

x77686d

#!/bin/bash
#
# cases:
#   cb ARGS     -- if any args, put them on the clipboard
#   cb | wc     -- stdin is a tty, send clipboard to stdout  
#   date | cb   -- stdin is not a tty, put stdin on clipboard
#
if [ $# -ne 0 ]
then
    echo -n $* | cb