#!/usr/bin/ruby -w

if ARGV.size != 2
   puts "#{$0} {input.txt} {template.txt} > {output.txt}"
   exit 1
end

# Load non-whitespace characters from input.
input = []
File.open(ARGV[0], "r") {|f|
   f.each_char{|c|
      if c.match?(/\S/)
         input += [c]
      end
   }
}

# Copy input characters to non-whitespace characters in template.
cursor = 0
File.open(ARGV[1], "r") {|f|
   f.each_char{|c|
      if c.match?(/\s/)
         print c
      else
         if cursor >= input.size
            # Template longer than input.
            exit
         end
         print input[cursor]
         cursor += 1
      end
   }
}