A simple Ruby program to convert horizontal text to vertical text.

y2t.rb

#!/usr/bin/env ruby -Ku -w

def resize(a, blank, s)
  num = s - a.size

  return a if num==0

  if num > 0
    num.times { a.push(blank) }
  else
    num.times { a.pop }
  end

  return a
end

def fit_size(l, blank)
  return [] if l.size == 0

  s = l.map{ |v| v.length }.max
  l.map { |a| resize(a, blank, s) }
end

def zip(l, blank)
  return [] if l.size == 0

  r = []
  l = fit_size(l, blank)
  l[0].size.times do |i|
    v = []
    l.size.times do |j|
      v.push(l[j][i])
    end
    r.push(v)
  end
  r
end

def drop_tail(a, blank)
  a.reverse.drop_while{|v| v==blank}.reverse
end

def trans(c)
  c += " " if c.count(c) == 1
  return c
end

def y2t(lines, blank, sep="")
  ys = lines.reverse.map { |l| l.chomp.each_char.map { |c| trans(c) } }
  ts = zip(ys, blank)
  ts = ts.map{ |l| drop_tail(l, blank).join(sep) }
  ts.join("\n")
end

puts y2t(STDIN.readlines, "　")