comment on

Hi..

I have a sample binary sample files begin file header (fixed length record) and data record (variable length record).

Sample data file as below:-

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 84 43 00 0c 00 00 11 09 08
43 49 29 60 64 0a 04 16 12 00 21 00 1b 00 00 65
09 08 44 80 90 0f 82 05 10 00 04 6e 06 08 ac 9b
02 67 00 00 00 7a 7f 00 69 53 54 4d 44 54 49 1f
00 6a 4b 43 47 48 51 42 3d 00
[download]

Based on sample file the header will be

While the data record will be

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 84 43 00 0c 00 00
11 09 08 43 49 29 60 64 0a 04 16 12 00 21 00 1b
00 00 65 09 08 44 80 90 0f 82 05 10 00 04 6e 06
08 ac 9b 02 67 00 00 00 7a 7f 00 69 53 54 4d 44
54 49 1f 00 6a 4b 43 47 48 51 42 3d 00
[download]

The variable length data contain TAG, LENGTH and DATA. Due to that i have to read the data length in order to get the real records. Below is my coding

#!/usr/bin/perl -w

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

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 @tt = ("Flags", "Record Seq.", "LAC Length", "Directory No", "Other
+s");
my @dtf = ("Year","Month","Day","Hour","Minute","Second", "Reserved","
+Duration");

my $outfile = $infile;
my $data;
my $i;

sub inttohex {
    my $int = shift;

    return sprintf ("%02X", $int);
}

sub hextoint {
    my $hex = shift;

    return sprintf ("%d", hex($hex));
}

## Convert each ASCII character to a two-digit hex number.
sub asctohex ()
{
        (my $hex = shift) =~ s/(.|\n)/sprintf("%02lx", ord $1)/eg;
        return $hex;
}

# Convert each two-digit hex number back to an ASCII character.
sub hextoasc 
{
        (my $asc = shift) =~ s/([a-fA-F0-9]{2})/chr(hex $1)/eg;
    return $asc;
}

sub strtoasc {
    my $str = shift;
    my $asc = "";
    my $loc = 0;
    my $i;

    for ($i = 0; $i < length($str); $i+=2) {
        $asc = $asc . hextoasc(substr($str, $loc, 2));
        $loc = $loc + 2;
    }

    return $asc;
}

my ($partnerdir_no);

if ($infile) {
    #open (OUTPUT, ">$outdir/$outfile");
    open (DATA, "$indir/$infile");
    binmode DATA;
    
    my @rec;

    until (eof DATA) {
        read (DATA, $data, 2);
        my $tag    = unpack "H2", substr $data,0,1,'';
        my $length = unpack "C", substr $data,0,1,'';
        $length -= 2;

        if ($length == "81") {
            $length = unpack "C", substr $data,0,1,'';
            $length -= 1;
        }
        my $loc = 0;

        while (read (DATA, $data, $length)) {
            my @header = unpack "H6 H2 H2 H12", substr $data,0,11,'';

            if ($trace) {
                printf ("%-20s : %-5s >%s<\n", "TAG" , $tag, inttohex(
+$tag));
                printf ("%-20s : %-5s >%s<\n", "RECORD LENGTH", $lengt
+h+2, inttohex($length+2));
                printf ("HEADER\n");
                for ($i=0; $i<@header; $i++) {
                    printf (" |- %-16s : %s\n", $tt[$i],$header[$i]);
                }
            }

            printf ("\nDATA PACKAGE\n");
            while ($data) {
                $tag = unpack "C", substr $data,$loc,1,'';
                printf ("%-20s : %-5s >%s<\n", "TAG", $tag, inttohex($
+tag));

                switch ($tag) {
                    # x64 - length fix 11 bytes
                    case 100 { @rec = unpack "C C C C C C C C3", subst
+r $data,0,10; 
                           printf " |- DateTime/Duration\n";
                           for (my $i=0; $i<8; $i++) {
                               printf "   |- %-20s : %02s >%s<\n", $dt
+f[$i], $rec[$i], inttohex($rec[$i]);
                              }
                       }
                    # x65 
                    case 101 { my $length = unpack "C", substr $data,0
+,1,'';
                           $length += 1;

                           if ($length == "81") {
                            $length = unpack "C", substr $data,0,1,'';
                            $length += 1;
                          }
                          $partnerdir_no = unpack "H*", substr $data,0
+,$length;
                          printf ("PARTNER DIRECTORY NO. : %s\n", $par
+tnerdir_no);
                    }
                }
            }    
        }
    }

    close(DATA);
    #close(OUTPUT);
}
[download]

But, my program read twice on the variable part ?. Why this is happened ?.. is it my coding is wrong ?.. please help me..

Thank you,

In reply to How to read variable data length ? by bh_perl

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		`&`
	<		`<`
	>		`>`
	[		`[`
	]		`]`

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.