# $Id: misc.rb 14 2008-03-02 05:42:30Z warchild $ # # Copyright (c) 2008, Jon Hart # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions are met: # * Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # * Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution. # * Neither the name of the nor the # names of its contributors may be used to endorse or promote products # derived from this software without specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY Jon Hart ``AS IS'' AND ANY # EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE # DISCLAIMED. IN NO EVENT SHALL Jon Hart BE LIABLE FOR ANY # DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES # (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND # ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. # module Racket module Misc # Return a number that is at most size bits long def Misc.randbits(size) bits = 0 srand Time.now.usec 0.upto(size-1) { bits <<= 1 bits |= rand(2) } bits end # Return a byte that is at most size bytes long def Misc.randbytes(size) bytes = 0 0.upto(size-1) { bytes <<= 8 bytes |= randbits(8) } bytes end # Return a string that is at most size characters long def Misc.randstring(size) s = "" 0.upto(size-1) { s += sprintf("%c", randbytes(1)) } s end # given a long representing a MAC address # print it out in human readable form def Misc.macaddr(long) long.to_s(16).rjust(12, '0').unpack("a2a2a2a2a2a2").join(":") end end end # vim: set ts=2 et sw=2: