Hi, all...

Another couple of funny things... with unpack() this time.

I'm opening a binary data file, setting binary mode... and then reading some blocks of data... but while I'm getting the data out of the file Ok, translating/mapping it into some useful variables is causing me all sorts of troubles.

In the attached code, the data is placed into the '$inbuf' string so that it is stored the same way as when I'm reading the data directly from the file.

What I'm expecting to get out of the code is something like:- 

       Format: (TBA)
   $event_len: 2Ex = 46
    $date_str: 4/10/2017
    $time_str: 00:00:00
$rec_type_idx: 10x = 16
 $source_name: !WV2   !
        $data: !CI=427 Lamp dim state=2 [SCATS=0].!
    $tail_len: 2Ex = 46

[download]

*Note: The 'C' near the start of the $data output is actually a 080x value. I didn't want to post a binary value here.

...but what I'm actually getting as an output is as follows (my attempts at using varying unpack() templates):- 

$inbuf: >.u[EOT]   [DLE]WV2   CI=427 Lamp dim state=2 [SCATS=0].<

        Format: C*
   $event_len: 2Ex = 46
    $date_str: 4/10/2017
    $time_str: 00:00:00
$rec_type_idx: 10x = 16
 $source_name: !87!
        $data: !86!
    $tail_len: 32x = 50

        Format: C8a6C*
   $event_len: 2Ex = 46
    $date_str: 4/10/2017
    $time_str: 00:00:00
$rec_type_idx: 10x = 16
 $source_name: !WV2   !
        $data: !128!
    $tail_len: 49x = 73

        Format: C8a*
   $event_len: 2Ex = 46
    $date_str: 4/10/2017
    $time_str: 00:00:00
$rec_type_idx: 10x = 16
 $source_name: !WV2   CI=427 Lamp dim state=2 [SCATS=0].!
        $data: !!
    $tail_len: 00x = 0

        Format: C8a6C33C1
   $event_len: 2Ex = 46
    $date_str: 4/10/2017
    $time_str: 00:00:00
$rec_type_idx: 10x = 16
 $source_name: !WV2   !
        $data: !128!
    $tail_len: 49x = 73

[download]

Note that the 0x2E byte is the 'length of record' and appears before and after the actual data record (hence, the 0x2E values at the bounds of the above array).

Here's the code I'm using: 


use strict;
use warnings;

my @data = ( 0x2E, 0x75, 0x0A, 0x04, 0x00, 0x00, 0x00, 0x10, 0x57, 0x5
+6, 
             0x32, 0x20, 0x20, 0x20, 0x80, 0x49, 0x3D, 0x34, 0x32, 0x3
+7, 
             0x20, 0x4C, 0x61, 0x6D, 0x70, 0x20, 0x64, 0x69, 0x6D, 0x2
+0, 
             0x73, 0x74, 0x61, 0x74, 0x65, 0x3D, 0x32, 0x20, 0x5B, 0x5
+3, 
             0x43, 0x41, 0x54, 0x53, 0x3D, 0x30, 0x5D, 0x2E );


my @formats = ( "C*", "C8a6C*", "C8a*", "C8a6C33C1" );
             
my $inbuf = join('', map { chr($_) } @data);  # Input buffer


printf("\$inbuf: >%s<\n", $inbuf);
printf("\n");

foreach my $fmt (@formats) {
   my $tmpbuf = $inbuf;  # In case something's being corrupted
   my ($event_len, $year, $mon, $day, $hour, $min, $sec, 
       $rec_type_idx, $source_name, $data, $tail_len) = unpack($fmt, $
+tmpbuf);
   
   my $date_str = sprintf("%s/%s/%s", $day, $mon, $year+1900);
   my $time_str = sprintf("%02d:%02d:%02d", $hour, $min, $sec);
      $rec_type_idx &= 0x1F;      # Only use b0-b6 
      
   printf("        Format: %s\n", $fmt);
   printf("   \$event_len: %02Xx = %d\n", $event_len, $event_len);   
   printf("    \$date_str: %s\n", $date_str);   
   printf("    \$time_str: %s\n", $time_str);   
   printf("\$rec_type_idx: %02Xx = %d\n", $rec_type_idx, $rec_type_idx
+);   
   printf(" \$source_name: !%s!\n", $source_name);   
   printf("        \$data: !%s!\n", $data);   
   printf("    \$tail_len: %02Xx = %d\n", $tail_len, $tail_len);   
   printf("\n");
   
}

[download]

Environment: ActiveState Perl v5.16.3, Windows 10 64-bit.

I'd greatly appreciate any clues as to what I should be trying to do with the unpack() template.

In reply to Problems Getting the Template Correct when Using unpack() by ozboomer

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