Hi folks!

I have to compile a string of unknown length (more than four bytes) in which several bits have to be set.

I can use

pack 'b*', $bitmap
to create a binary string from a sequence of '0's and '1', e.g. '1100111010'

With this I just have to create my bitmap with something like:

$bitmap = '0' x 64;
substr($bitmap, 0, 1) = '1';
substr($bitmap, 0, 4) = '1';
substr($bitmap, 0, 5) = '1';
substr($bitmap, 0, 14) = '1';
$binary = pack('b*', $bitmap);

[download]
This is very tedious if there are more than a handfull of bits to set.

Next problem is to check if a bit is set in a binary string.
The normal way of ANDing the string won't work because of the size of the string.

I haven't checked Math::BigInt, perhaps that is a simple solution.

Any Ideas?

In reply to how to set bits in an arbitrary length string by busunsl

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