in reply to Handling Hex data with Dynamic unpack

This is how I would start, but I'd need more complete spec 

#!/usr/bin/perl --
use strict; use warnings;
use Data::Dump;

my $rawAsHex = q'0001000000004f914f1c0b0100425343413030000000050000434
+130303030300000000143413030303134000000024341303030323200000003434130
+3030323400000004434130303032390000000100224e43656c6c30000000020042534
+341303100000005000543413031303031000000064341303130303400000007434130
+31303130000000084341303130313500000009434130313031360000000100224e436
+56c6c30000000030042534341303200000006000a';
my $raw = pack 'H*', $rawAsHex;
my @stack = unpack q{
A2 ### Header Record Id : 1 Byte
A2 ### File Format Version : 1 Byte
A16 ### Timestamp : 8 Bytes
A2 ### No. of BSCs : 1 Byte
   ###     For each BSC ...
A2 ###     BSC Id : 1 Byte
A2 ###     Application Version : 1 Byte
A4 ###     BSC Name : 2 Bytes
A4 ###     Number of Cells : 2 Bytes
   ###         For each Cell ...
A4 ###         Cell Pointer : 2 Bytes
A18 ###         Cell Name : 9 Bytes
A4 ###         Number of Neighbour Cells : 2 Bytes
   ###             For each Neighbour Cell to this BSC ...
A4 ###             Cell Pointer : 2 Bytes
A18 ###             Cell Name : 9 Bytes
}, $rawAsHex;

my $id      = unpack 'C*', pack 'H*', $stack[0];
my $version = unpack 'C*', pack 'H*', $stack[1];
my $time    = unpack 'H*', pack 'H*', $stack[2]; ## WHAT?!

dd [ $id, $version, $time , \@stack ];
__END__
[
  0,
  1,
  "000000004f914f1c",
  [
    "00",
    "01",
    "000000004f914f1c",
    "0b",
    "01",
    "00",
    4253,
    4341,
    3030,
    "000000050000434130",
    3030,
    3030,
    "000000014341303030",
  ],
]

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Re^2: Handling Hex data with Dynamic unpack
by PerlJedi (Novice) on Jul 05, 2012 at 11:17 UTC

    Hey Thanks Anonymous Monk ... It certainly is a good starting point. I appretiate your replies :)

    Thanks and Regards,

    PerlJedi

[reply]
Re^2: Handling Hex data with Dynamic unpack
by PerlJedi (Novice) on Jul 05, 2012 at 11:28 UTC
    Some how perl doesn't allow me to unpack like this (look at H2 H2 H16 H2 A2 ...) : 
    my @stack = unpack q{
H2 ### Header Record Id : 1 Byte
H2 ### File Format Version : 1 Byte
H16 ### Timestamp : 8 Bytes
H2 ### No. of BSCs : 1 Byte
   ###     For each BSC ...
A2 ###     BSC Id : 1 Byte
A2 ###     Application Version : 1 Byte
A4 ###     BSC Name : 2 Bytes
A4 ###     Number of Cells : 2 Bytes
   ###         For each Cell ...
A4 ###         Cell Pointer : 2 Bytes
A18 ###         Cell Name : 9 Bytes
A4 ###         Number of Neighbour Cells : 2 Bytes
   ###             For each Neighbour Cell to this BSC ...
A4 ###             Cell Pointer : 2 Bytes
A18 ###             Cell Name : 9 Bytes
}, $rawAsHex;

    [download]

    Any idea how this could be done?

    I get a output like this :

    [
  48,
  48,
  "3031303030303030",
  [
    30,
    30,
    "3031303030303030",
    30,
    "04",
    "f9",
    "14f1",
    "c0b0",
    1004,
    "253434130300000000",
    5000,
    "0434",
    "130303030300000000",
  ],
]

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[d/l]
[select]

      Some how perl doesn't allow me to unpack like this (look at H2 H2 H16 H2 A2 ...) ... Any idea how this could be done?

      I showed you how. What you're dealing is a text-strings, so if you want bytes, you have to pack them. First pack them to get bytes ( pack 'H*' ) then pack them to get what you're really after ( C An unsigned char (octet) value. ) .....

      Commands 

      perl -le " print unpack q{H*}, q{Y} "
perl -le " print pack q{H*}, q{59} "
perl -le " print ord q{Y}
perl -le " print  pack q{H*}, q{59} "
perl -le " print  unpack q{C}, pack q{H*}, q{59} "

      [download]

      Session 

      $ perl -le " print unpack q{H*}, q{Y} "
59

$ perl -le " print pack q{H*}, q{59} "
Y

$ perl -le " print ord q{Y}
89

$ perl -le " print  pack q{H*}, q{59} "
Y

$ perl -le " print  unpack q{C}, pack q{H*}, q{59} "
89

      [download]

      Y encoded as hex is 59

      The numeric value ( ord ) of Y is 89

      The C An unsigned char (octet) value, 8-bits, 1-byte of Y is 89

[reply]
[d/l]
[select]

        Okie ... will try :)

        Thanks once again.

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