I have a situation where I need to convert a binary value to hex in Ruby. My situation is as 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.
"0x%02x"%"1".to_i(2) #=> "0x01".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/
'1111'.each_byte.map { |b| b.to_s(16) }.join => "31313131" (And I want "f" or something similiar.)
'1111' has four bytes, and each has a value of 49 (ie, the ASCII value). 49 in decimal is 31 in hex. You don't have a "binary" value in the sense that the question is talking about. You have a string containing ASCII characters '1' and '0'.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.
String#% (a.k.a. sprintf) instead of to_s to format the number appropriately - using %02x to format the number as a hexadecimal number padded to 2 digits using 0s. However this does not work if you want a base other than 16 (or 10 if you use d instead of x), as % does not allow you to pick an arbitrary base. Alternatively you can use to_s followed by String#rjust, which works with arbitrary bases and padding characters.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)
