Originally i tried to ask in the chatterbox, but i think that i may have mis-translated what i am trying to do. So without further ado:

I have an ogg/opus audio file that i am trying to read the header, which is 28 bytes or 0x1C in length. Here is the code i am using to read this header:

#!/usr/bin/perl
use strict;
use warnings;
                        
open my $ogg_file, '<', shift or die $!;
binmode($ogg_file);

read_ogg_header($ogg_file);

sub read_ogg_header {
    
    my ( $file ) = @_;
    
    read($file, my $buf, 28 );

    my ( $ogg_magic, $ogg_version, $flags, $granule_position, $serial_
+number, $sequence_number, $checksum, $total_segments, $segment_size )
+ = unpack('C4 C1 C1 C8 C4 C4 C4 C1 C1', $buf);

    print $ogg_magic;  ### Expected it to print 'OggS'
}

[download]
and here is the 28 byte header: 
0x4F6767530002000000000000000083CA3DC0000000009F59730A0113

[download]

The more i think about this the more i wonder if unpack C is not what i want to do anyway. are the single bytes already in unpack C format? if so, how can i just store that value into the variable without any conversion so any further printing or processing the actual raw values eg print $ogg_magic will print "OggS"

Or maybe i am just completely confused by pack and unpack. i can use read() and i can easily print those values or translate them into expected formats, but i think unpack C is messing me up somehow? or ... OR... maybe i am just completely confused. If i need to elaborate any more please just let me know.

P.S. i guess what i am wondering in the end is, how can i make pack or unpack assign the same values as read($file, my $buf, n);? i can work with whatever data read stores (im assuming binary?) but i cannot get the same values/data to store in those variables with unpack or pack. hope i am clear, if not just give me a swift kick in the hind quarters and tell me what other info you need. and as always any help is certainly appreciated :)

In reply to pack/unpack woes by james289o9

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