#!/usr/bin/python

# -----------------------------------------------------------------------------
#  Implements a Vigenère square; shifts input file by all possible values
#
#               (c) 2004 Jason Bittel
# -----------------------------------------------------------------------------

import os
import sys
import string

# -----------------------------------------------------------------------------
class g:
   alpha = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', \
            'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', \
            'U', 'V', 'W', 'X', 'Y', 'Z' ]

# -----------------------------------------------------------------------------
def parseFile(infile, shift):
   """
   """
   str = ""

   try:
      input = open(infile)

      for line in input:
         for char in line:
            char = string.upper(char)

            if char.isalpha():
               index = g.alpha.index(char) + shift
               if index > 25:
                  index -= 26

               str += g.alpha[index]
            else:
               str += char

      print str, "  [" + repr(shift) + "]"

      input.close()
   except IOError, err:
      sys.stderr.write("Error: unable to access %s: %s\n" % (infile, err.strerror))
      sys.exit()

# =============================================================================
def main():
   """
   """
   if not len(sys.argv) == 2: # Check for command line arguments
      print "Usage: %s [ filename ]\n" % os.path.basename(sys.argv[0])
      sys.exit(0)

   for n in range (1, 26):
      parseFile(sys.argv[1], n)

if __name__ == "__main__": main()