packing hex

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I have a string of hexadecimal numbers like

$a = '9b23b4b322b0da70';

and I want to convert it to a binary string. Is there a simple way to do this using pack() or vec()? currently I am thinking of splitting the string every two characters, and doing chr() on each of them, but I think this is probably not the best way, is it?

Comment on packing hex Download Code

Replies are listed 'Best First'.
Re: packing hex by rob_au (Abbot) on Dec 30, 2003 at 08:54 UTC
You will want to take a look at the pack and unpack functions and the corresponding tutorial, Pack/Unpack Tutorial (aka How the System Stores Data), on this site - Another example of pack/unpack usage can also be seen in my signature. `rob@development:/home/rob$ perl -e '$str = pack("H*", "9b23b4b322b0da7 +0")'` [download] `perl -le "print+unpack'N',pack'B32','00000000000000000000001010100101'"`	[reply] [d/l]
Re: packing hex by Taulmarill (Deacon) on Dec 30, 2003 at 09:00 UTC
`$hex = pack ( "H", $a ); $bin = unpack ( "B", $hex ); print "$bin\n";` [download]	[reply] [d/l]
Re: packing hex by davido (Cardinal) on Dec 30, 2003 at 17:05 UTC
The tutorial that really helped me with pack and unpack the most was from Perl's POD: perlpacktut. It has a lot of great examples, and a pace that I found interesting but not overwhelming at first. Update: rob_au mentioned that perlpacktut is only available in Perl 5.8.0 or later. So for those who are still using pre 5.8.0 Perls, you may have to use http://www.perldoc.com to read perlpacktut. Hope this helps! Dave	[reply]