Hex string to bytestring

ruby-talk
1

I have strings of this form: "0x0253000c"

These are supposed to represent four hex values. I want a string each of
whose "characters" (bytes) is one of those hex values, in order, like
this: "\002S\000\f"

I can transform the given string like this:

s = "0x0253000c"
output = ""
s = s[2..-1]
s.split(//).each_slice(2) do |ss|
  output << ss.join.hex.chr
end
p output # => "\002S\000\f"

Great, but this seems idiotic. There must be some simple neat way that
I'm not seeing. Could you tell me what it is? Thx - m.

···

--
matt neuburg, phd = matt@tidbits.com <http://www.tidbits.com/matt/>

2

well, i dont find that "idiotic" so to speak...
but try this eg,

["0253000C"].pack "H*"
=> "\x02S\x00\f"

kind regards -botp

···

On Sun, Jul 22, 2012 at 10:42 AM, Matt Neuburg <matt@tidbits.com> wrote:

s = "0x0253000c"
output = ""
s = s[2..-1]
s.split(//).each_slice(2) do |ss|
  output << ss.join.hex.chr
end
p output # => "\002S\000\f"

Great, but this seems idiotic.

3

Perfect; I had tried unpack but not pack. So this will work for the
strings I am getting:

output = [s[2..-1]].pack("H*")

Thanks! m.

···

botp <botpena@gmail.com> wrote:

On Sun, Jul 22, 2012 at 10:42 AM, Matt Neuburg <matt@tidbits.com> wrote:
> s = "0x0253000c"
> output = ""
> s = s[2..-1]
> s.split(//).each_slice(2) do |ss|
> output << ss.join.hex.chr
> end
> p output # => "\002S\000\f"
>
> Great, but this seems idiotic.

well, i dont find that "idiotic" so to speak...
but try this eg,

["0253000C"].pack "H*"
=> "\x02S\x00\f"

--
matt neuburg, phd = matt@tidbits.com <http://www.tidbits.com/matt/&gt;