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codecaine · 05-15-2010, 10:41 PM

This code lets you encode a file into binary format using ones and zeros. You can also convert it back to plain text.

Code:

=begin

    This program encodes a file to binary or decodes it to plain text

    coded by codecaine aka Jerome Scott II

=end

#converts each text character to an 8 bit binary string and returns the string

def text2bin(text)

  pad = '' #pads an binary string with 0's

  size = 0 #stores the size of the binary string

  start_str = 0 #start point of the text string

  start_str.freeze #make start_str constant (This is optional)

  bin_bitsize = 8 #holds the size of the binary string

  bin_bitsize.freeze #mae bin_bitsize constant (This is optional)

  bin_str = '' #holds all the binary values of the text

  tempstr = '' #temporary old an 8 bit binary string to be appended

  start_str.upto(text.length - 1) do |i| #loop through the text giving to the function

    size = text[i].to_s(2).length #get the size of the binary string

    tempstr = text[i].to_i().to_s(2) #convert a character to a binary string

    if size < bin_bitsize #if the binary string is less then 8 bits pad the binary string

      pad = '0' * (bin_bitsize - size) #pad the binary string with 0's to equal 8 characters

      bin_str.concat(pad.concat(tempstr)) #append the 0's at the beginning of the binary string

      end

 end

 return bin_str #return the text as a binary string

end

def bin2text(bin) #converts 8 bit binary text to plain text

  tempstr = '' #temporary string to hold 8 bit binary string

  plain_text = '' #holds the plain text data converted from 8 bit binary string

  start_str = 0 #holds the index for the beginning of a string

  start_str.freeze #make start_str a constant (This is optional)

  start_str.upto(bin.length - 1) do |i| #loop through the binary string

    tempstr.concat(bin[i].chr) #append binary text to the temporary string

    if (i+1) % 8 == 0 #if the binary string reaches 8 bits convert it to plain text

      plain_text.concat(tempstr.to_i(2).chr) #converts the binary string to an character and append it to plain text

      tempstr = '' #empty text from tempstr

    end

  end

  return plain_text #return the binary string in plain text

end

def usage #Instructions on how to use this program

puts 'Usage:'

puts '    -e encodes to binary file -d decodes to binary file'

puts 'Example:'

puts '    ruby bin_encoder.rb -e plain_textfile.txt encoded_file.txt'

puts '    ruby bin_encoder.rb -d encoded_file.txt plain_textfile.txt'

end

encode_file = '' #hold encode file name

decode_file = '' #holde decode file name

ENCODE = '-e' #encode value constant

DECODE = '-d' #decode value constant

MIN_ARGUMENTS = 3 #holds minute amount of arguments required

begin

if ARGV.length >= MIN_ARGUMENTS #if the arguments equal or greater than minium arguments continue else execute help method

    OPTION = ARGV[0] #constant hold that -e for encode or -d for decoding

    INPUT_FILE = ARGV[1] #constant for input file name

    OUTPUT_FILE = ARGV[2]  #constant for output file name

      if OPTION == ENCODE #if user choose encode option encode the file to binary

          fr = File.open(INPUT_FILE,'r') #open plain text file for reading

          encode_file = text2bin(fr.read) #read plain text file

          fr.close #close the file

          fw = File.open(OUTPUT_FILE,'w') #open file for output

          fw.write(encode_file) #encode the file read into binary

          fw.close #close file

          puts "file encoded into binary format as #{OUTPUT_FILE}" #show that the file has been encoded

     elsif OPTION == DECODE #if user choose decode option decode the file to plain text

        fr = File.open(INPUT_FILE,'r') #open file for reading

        decode_file = bin2text(fr.read) #decode binary file to plain text

          fr.close #close file

          fw = File.open(OUTPUT_FILE,'w') #open file for writing

          fw.write(decode_file) #write decoded text to file

          fw.close #close file

          puts "file encoded into binary format as #{OUTPUT_FILE}" #show that the file has been decoded

      end

else

    usage #usage method

end

rescue Exception => e#if there were any error show the error message and display usage

    puts "Error: #{e}"

    usage

end