in reply to Re^4: [pack]little endian timestamp to decimal value
in thread [pack]little endian timestamp to decimal value

absolutely...there's no way for a program to magically work out if a number is big or little endian. So the script somehow has to know that and use the appropriate kind of pack/unpack. or you could even just swap half the string around using string manipulation, before coalescing to decimal. either way it has to be known which way the endian goes. if these numbers are some well known numbers (say serial numbers for a computer product) then they usually already have some logic encoding to them, which could give you a clue. e.g. leftmost decimal 4 digits a valid vendor code in a known list, etc.
the hardest line to type correctly is: stty erase ^H
  • Comment on Re^5: [pack]little endian timestamp to decimal value

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Re^6: [pack]little endian timestamp to decimal value
by timtowtdi (Sexton) on Oct 27, 2010 at 08:52 UTC
    I'm not joking!
    I now tried it on 5 different machines with different Perl versions.

    1 PowerPC (PowerBook G4, running Gentoo Linux) Perl 5, version 12, subversion 2 (v5.12.2)
    1 PowerPC (PowerMac G4, running Gentoo Linux) Perl v5.8.8 built for powerpc-linux
    1 PowerPC G5 (PowerMac G5, running OS X 10.5) Perl v5.8.9 built for darwin-2level
    1 Dual Xeon (MacPro running OS X 10.6) Perl v5.8.9 built for darwin-2level
    1 Dual Xeon (Dell hardware Fedora Core 7) Perl v5.8.8 built for i386-linux-thread-multi


    And on all the PowerPCs I get as return: "3059448640"
    And on all the Intels I get as return: "1081826230"


    (Just to be clear: I tried running the code from the same share. And I typed it in all over.)
    #!/usr/bin/perl -w

print unpack "L", pack "H*", "B65B7B4000";

    [download]
    The great mistake is to anticipate the outcome of the engagement; Let nature take it's course, and your tools will strike at the right moment.
[reply]
[d/l]
      Where has the < sign hidden?
[reply]
      That's not the code I provided.
[reply]
        I think I'm getting retarded. :S

        You are right. That was not the code.
        I now tried it with this:
        #!/usr/bin/perl -w

$le_ts = "B65B7B4000";
print unpack "L<", pack "H*", $le_ts;

        [download]
        It now runs on all architectures.
        The great mistake is to anticipate the outcome of the engagement; Let nature take it's course, and your tools will strike at the right moment.
[reply]
[d/l]

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