Generate a hex string from integers

Ruby
1

Hi there,

I’m new in Ruby. So, my question can seem simple for you. I need to
generate a hex string from some digits: 1, 114, 3, 2 for example. I need
the following hex representation: 00010072030002 - (0x0001, 0x0072,
0x03, 0x0002).
I tried to use pack:

a = [1, 114, 3, 2]
hexStr = a.pack(‘iisi’)

but it generate following string: 10007200302000

Also, what is the best way to convert this hex string into digits back?

Thanks in advance.

Michael

2

On 17/06/06, Xavier N. [email protected] wrote:

irb(main):002:0> sprintf “%04x”*4, 1, 114, 3, 2
=> “0001007200030002”

Not a bad idea, but that won’t exactly do it: he wants only one octet
for the 3.

Try this:

hex_str = a.pack(‘nnCn’).unpack(‘H*’)[0] # => “00010072030002”

Paul.

3

On Jun 17, 2006, at 20:52, Michael stepanov wrote:

I’m new in Ruby. So, my question can seem simple for you. I need to
generate a hex string from some digits: 1, 114, 3, 2 for example. I
need
the following hex representation: 00010072030002 - (0x0001, 0x0072,
0x03, 0x0002).

sprintf to the rescue!

irb(main):002:0> sprintf “%04x”*4, 1, 114, 3, 2
=> “0001007200030002”

– fxn

4

On Jun 17, 2006, at 21:58, Paul B. wrote:

irb(main):002:0> sprintf “%04x”*4, 1, 114, 3, 2
=> “0001007200030002”

Not a bad idea, but that won’t exactly do it: he wants only one
octet for the 3.

Oh yes, I didn’t note the 3 was different (I guess it is different
from the rest because of the semantics of the wanted string). With
sprintf that would be

sprintf “%04x%04x%02x%04x”, 1, 114, 3, 2

– fxn

5

On 6/17/06, Michael stepanov [email protected] wrote:

hexStr = a.pack(‘iisi’)
Posted via http://www.ruby-forum.com/.

[1, 114, 3, 2].map{|n| “%04x” %n}.join

Hope that helps
Robert

Deux choses sont infinies : l’univers et la bêtise humaine ; en ce qui
concerne l’univers, je n’en ai pas acquis la certitude absolue.

  • Albert Einstein
6

2006/6/17, Robert D. [email protected]:

[1, 114, 3, 2].map{|n| “%04x” %n}.join

A bit more efficient

irb(main):005:0> a.inject(“”) {|s,i| s << “%04x” % i}
=> “0001007200030002”

Kind regards

robert

7

Robert K. wrote:

2006/6/17, Robert D. [email protected]:

[1, 114, 3, 2].map{|n| “%04x” %n}.join

A bit more efficient

irb(main):005:0> a.inject(“”) {|s,i| s << “%04x” % i}
=> “0001007200030002”

Thanks a lot, guys, for your answers. You helped me a lot!