in reply to HEX to floating point

You can change the endianess of a whole string of binary data using scalar reverse, so long as you remember to reverse the template and results: 

$raw = pack 'H*',  '00000034000031b10191403b8811bb1366e4';;

print for reverse unpack 'dCCVV', reverse $raw;;
52
12721
1
145
27.53152055

[download]

If you're working with large volumes of binary structures, doing it this way can save quite a lot of time.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

Replies are listed 'Best First'.
Re^2: HEX to floating point
by Spooky (Beadle) on Jun 16, 2008 at 14:47 UTC
    This is what I'd like to be able to do but when I entered your code into a file with the PERL load module I didn't get anything like your output - I did get a huge floating point number! ..any suggestions - I am new at PERL as if you didn't already guess... Here's my file: #!/fs/COTS/gnu/bin/AIX/perl $raw = pack 'H*", '00000034000031b110191403b8811bb1366e4'; print for reverse unpack 'dCCVV', reverse $raw ; ..when I run this (simply type "test.pl") I get : 1331232565922520241.709119561536
[reply]

      First, you have a typo in your hex string: '00000034000031b110191403b8811bb1366e4' (the highlighted 1).  Second, if you run this on AIX (as I figure from the presence of "AIX" in the shebang path), you most likely don't want the reverse stuff anyway, as AIX typically runs on big-endian hardware, which already matches the binary format of your numbers...

      In other words, on AIX, this should work (actually it does — tried it): 

      my $raw = pack "H*", '00000034000031b10191403b8811bb1366e4';
print "$_\n" for unpack 'NNCCd', $raw;

      [download]
[reply]
[d/l]
[select]
        Thanks so much - it work's great! One other question: what would be the best way to assign each value to a variable name? Again, thanks for your help - I'm definitely sold on PERL even though I'm a novice.
[reply]
      I entered your code into a file with the PERL load module

      Hm. I'm afraid I have no idea what that means? What is the "Perl load module"?

      Perhaps you could cut & paste the terminal session to show what you did?

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
        This is what I'd like to be able to do but when I entered your code into a file with the PERL load module I didn't get anything like your output - I did get a huge floating point number! ..any suggestions - I am new at PERL as if you didn't already guess... Here's my file: #!/fs/COTS/gnu/bin/AIX/perl $raw = pack 'H*", '00000034000031b110191403b8811bb1366e4'; print for reverse unpack 'dCCVV', reverse $raw ; ..when I run this (simply type "test.pl") I get : 1331232565922520241.709119561536
[reply]

In Section Seekers of Perl Wisdom