use 5.12.0;
my $raw = "\003\003\003abcdef";
my @offsets = unpack '(C)3', $raw;
my $chucks = join ' ', map { '@' . $_ . 'a' }  @offsets;
say $chucks;
say for unpack $chucks, $raw;
use 5.12.0;
my $raw = "\003\003\003abcdef";
my @offsets = unpack '(C)3', $raw;
my $chucks = join ' ', map { '@' . $_ . 'a' }  @offsets;
say $chucks;
say for unpack $chucks, $raw;
__END__
@3a @3a @3a
a
a
a