I am struggling to understand the more advanced (un)pack templates, which allow me to describe my data structure.
I have this structure packed in a string $testinput
byte: number of members in each of the following arrays
array of bytes
array of unsigned shorts
another array of unsigned shorts
I would like to know, if there is a single unpack template,
that uses the first entry not only for sizing the following array, but instead three times for each of them.
This is what I have tried so far, and I am not really happy with it.
my $testinput = pack('C/a* a* a*',
(pack 'C*', 1, 2),
(pack 'v*', 3, 4),
(pack 'v*', 5, 6));
print join(',', unpack('C/C* v2 v2', $testinput)), "\n";
# gives "1,2,3,4,5,6" which is ok,
# but has the repeat factors for 'v' hardcoded
my $repeat = unpack('C', $testinput);
print join(',', unpack("C/C* v$repeat v$repeat", $testinput)), "\n";
# gives "1,2,3,4,5,6" which is ok, but uses two steps
Is it possible to use one call to unpack to expand this string to the values above?
Thanks in advance, hexcoder