The assignment to the array will eat up all the values so no you can't do it in just one go (if the array comes before the individual scalars; if the scalars came first it would have just worked as you have it now); you could however capture everything in @ids then use splice or pop to remove $text and $length afterwards.

Update: D'oh, yeah it'll work fine with a slice of fixed length as psini proffers below. Ned moar caffeine apparently . . .

Update 2: Well, will work with a more appropriate unpack string ("c40" returns a list of 40 characters-as-numbers, not a string of 40 characters); "a", "A", or "Z" is probably more what the OP's looking for.

use strict;
use warnings;

use YAML::Syck qw( Dump );

my $src = pack( "N10 a5 n", 0..9, "abcde", 99 );

my( @a, $b, $c );
(@a[0..9],$b,$c) = unpack( "N10 a5 n", $src );

print Dump( { a => \@a, b => $b, c => $c } ), "\n";

exit 0;

__END__
--- 
a: 
  - 0
  - 1
  - 2
  - 3
  - 4
  - 5
  - 6
  - 7
  - 8
  - 9
b: abcde
c: 99
[download]