What endianess? I would go straight for Convert::Binary::C

But, does this look like something you want? 

$ perl -le " print unpack q/ b64 /, pack q/a8/, 4294967295  "
0010110001001100100111000010110010011100011011001110110001001100

$ perl -le " print unpack q/ b64 /, 4294967295  "
0010110001001100100111000010110010011100011011001110110001001100

use constant CAN_PACK_QUADS => !! eval { my $f = pack 'q'; 1 };
sub UInt64 { unpack( ( CAN_PACK_QUADS  ? 'Q<' : 'a8' ), $_[-1] ) }

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In reply to Re: Convert unsigned long int (64bit) to binary string(64bits) (endianness? Convert::Binary::C) by Anonymous Monk
in thread Convert unsigned long int (64bit) to binary string(64bits) by Ergometer

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