Converting a binary value to hexadecimal in Ruby

I have a situation where I need to convert a binary value to hex in Ruby. My situation is as 开发者_StackOverflow中文版follows:

When bin = "0000111", my output should be: hex = "07".

When bin = "010001111", my output should be: hex = "08f".

Could someone help me out on how to do this? Thanks in advance.

How about:

>> "0x%02x" % "0000111".to_i(2) #=> "0x07"
>> "0x%02x" % "010001111".to_i(2) #=> "0x8f"

Edit: if you don't want the output to be 0x.. but just 0.. leave out the first x in the format string.

def bin_to_hex(s)
    s.each_byte.map { |b| b.to_s(16).rjust(2,'0') }.join
end

Which I found here (with zero padding modifications):

http://anthonylewis.com/2011/02/09/to-hex-and-back-with-ruby/

Both String#to_i and Integer#to_s take an optional integer argument specifying the base. So you can convert your binary string to an integer using base 2 and then convert that integer back to a string using base 16.

You can use the unpack method on string pointing the target to be hex

def bin_to_hex(binary_string)
  binary_string.unpack('H*').first
end

Refer to: https://apidock.com/ruby/String/unpack

I found it to be much more clean than the solutions listed above.

as state above by @Michael Kohl easiest way, define method with the action

  # if you don't want the output to be 0x.. but just 0.. leave out the first x in the format string.
  def self.bin_to_hex(string)
    "0x%02x" % "#{string}".to_i(2)
  end

and use the method like this

string = "00011110"
puts bin_to_hex(string)
=> 0x1e

remember these are still ASCII representations, in case you want to encode it and send bytes as HEX (send via UDP or low level protocols) just do:

value = self.bin_to_hex(value)
bytes = [value]
bytes.pack('H*' * bytes.size)