I find the synopsis of Convert::ASN1 quite clear:

  use Convert::ASN1;

  $asn = Convert::ASN1->new;
  $asn->prepare(q<

    [APPLICATION 7] SEQUENCE {
      int INTEGER,
      str OCTET STRING
    }

  >);

  $pdu = $asn->encode( int => 7, str => "string");

  $out = $asn->decode($pdu);
  print $out->{int}," ",$out->{str},"\n";
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Where exactly do you have problems?

Actually, I have asn.1 file and the sample as below.

My problem is how could i read ASN.1 data and display the value ? I did not know how to do that and I could not macthed your program with my data.

9f a1 0b 00 9f a1 0b 00 9f be 00 02 00 15 9f be
01 81 0f 01 55 18 f3 0b 24 99 20 10 00 10 00 00
00 01 9f be 19 81 09 00 01 10 60 18 00 38 38 11
9f be 1b 08 02 01 10 ff ff ff ff ff a1 06 82 04
04 00 00 00
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I guess that ASN1 expects you to supply the data description. So you would have to have the description of your data somewhere in your documentation. You don't show your data description at all here, so I don't know what it is.

After you've created the ASN decoder using the description, you pass it data to decode. That's it.

You've posted a hexdump of your data for the second time. What do you expect us to do with that hexdump?

Where exactly do you have problems? You haven't shown a single line of code, so that makes it kinda hard for me to give you more concrete help than pointing you to the module documentation.

Do you know what your example data is/represents/contains? Do you have an ASN1 decription of it?

This is file description:

The format of a Tag is as follow:
                       Identifr    Filler    Length    Data
Where 
      Identifier : A 3 bytes long number uniquely identifies the Tag
      Filler     : A filler of with value H’81 is inserted at position
+ on condition number of data bytes sent in the AXE signal is odd. 
      Length     : is the number of  taaged data in bytes.
      Data       : is the actual data in the tag

Identifier    Filler Length_of_data    <data>
9FA10B        -      00                <data>
9FA001          81     03                <data>
9FBF7B          81     0F                <data>
9FBF7D          81     00-0F             <data>
9FBE00          -      0E                <data>
9FBE00          -      0E                <data>
9FBE1A          81     00-0F             <data>
9FBE1B          81     00-0F             <data>
9FBE1C          81     00-0F             <data>
9FBE1D          81     00-0F             <data>
9FA016          81     00-02             <data>
9FBE19          81     00-0E             <data>
9FA10B          -      00                <data>
9FBE00          -      02                <data>
9FBE01          81     0F                <data>
9FBE19          81     01-0E             <data>
9FBE1B          81     01-11             <data>
9FA10B          -      00                <data>
9FA001          81     03                <data>
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Wherever you are obtaining your ASN.1 dataset, should also supply you with or make available to you, an ASN.1 description (template) of the format of the data within that dataset.

For example, if you are downloading .aso files from NCBI, then somewhere within their site/ftp there will be a file containing the ASN.1 description that looks something like this one. In that same directory there are several other .prt files, one of which would form the the input to Convert::ASN1 (or possibly better, Bio::ASN1::Sequence), if they are the source of your dataset.

Reverse engineering an ASN.1 description based upon the limited information you've provided above (where did that come from?) is iffy at best.

---

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."

Here is a simple (non-ASN.1) decoder based on your specification:

    #!/usr/bin/perl -w

    use strict;

    my $message = pack 'H*', join '', qw(
        9f a1 0b 00 9f a1 0b 00 9f be 00 02 00 15 9f be
        01 81 0f 01 55 18 f3 0b 24 99 20 10 00 10 00 00
        00 01 9f be 19 81 09 00 01 10 60 18 00 38 38 11
        9f be 1b 08 02 01 10 ff ff ff ff ff a1 06 82 04
        04 00 00 00
    );

    _unpack_message($message);

    sub _unpack_message {

        my $message = shift;

        print "Tag     Length  Data\n";

        while ($message) {
            my $tag     = unpack 'H6', substr $message, 0, 3, '';
            my $length  = unpack 'C',  substr $message, 0, 1, '';

            if ($length == 0x81) {
                $length = unpack 'C',  substr $message, 0, 1, '';
            }

            my $template = 'H' . $length * 2;
            my $data     = unpack $template, substr $message, 0, $leng
+th, '';

            printf "%s  %-6d  %s\n", $tag, $length, $data;
        }
    }

    __END__
    Prints:

    Tag     Length  Data
    9fa10b  0       
    9fa10b  0       
    9fbe00  2       0015
    9fbe01  15      015518f30b24992010001000000001
    9fbe19  9       000110601800383811
    9fbe1b  8       020110ffffffffff
    a10682  4       04000000
[download]

--
John.

Hi..
This is my program but I have seen that the substr is not subtring the data correctly. Please help me


#!/usr/bin/perl -w

use Cwd;
use warnings;
use strict;
use Getopt::Long;

use constant FILEHDR => 4;
use constant CDRLEN  => 286;

my ($trace, $help, $infile);
my $swap = '';
my $indir  = getcwd;
my $outdir = getcwd;

GetOptions (
    "h|help"    => \$help,
    "filename|f=s"    => \$infile,
    "swap|s"    => \$swap,
    "input|i=s"    => \$indir,
    "output|o=s"    => \$outdir,
    "trace|t"    => \$trace
) or usage();


sub usage {
    exit;
}

my $outfile = $infile;
my $data;

if ($infile) {
    #open (OUTPUT, ">$outdir/$outfile");
    open (DATA, "$indir/$infile");
    binmode DATA;
    
    while ($data = <DATA>) {
        my $tag    = unpack "H2", substr $data,0,1,'';
        my $length = unpack "C", substr $data,0,1,'';

        if ($length == 0x81) {
            $length = unpack "C", substr $data,0,1,'';
        }

                # Problem is here.. data not substr correctly
        my $template = 'H' . $length*2;
        my $rec      = unpack $template, substr $data,0,$length,'';

        printf ("RECORD TAG    : %s\n", $tag);
        printf ("RECORD LENGTH : %s\n", $length);
        printf ("RECORD        : %s\n", $rec);
    }

    close(DATA);
    #close(OUTPUT);
}
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This is sample file


84 47 00 0c 00 00 11 0a 03 50 35 04 00 64 0a 04
16 12 00 1e 00 1d 00 00 65 09 08 54 52 03 2f 82
05 10 00 02 6e 06 0b a8 53 11 67 00 00 00 7a 7f
00 69 4a 42 47 48 4a 41 0c 00 6a 53 54 4d 44 54
4f 1c 00 66 04 00 00
[download]