Re: Converting a String of bits into a binary number in perl?

[Steven Lembark]

-- Deepak Mallya <[EMAIL PROTECTED]>

Hi,
    Can anyone tell me how do I convert a String of bits into a binary
number in Perl

For eg:- $a="100";  I want to convert this into perl's interpretation of
binary no ie $a=0b100

You have to mask the value to 32 bits and then use
"unpack". Issue is that with a string you may have
more than the upper limit of bits, which will lead
to overflows (or having to use BigIntegers ).

One apprach that uses a simpler pack string is

   my @intz = ();

   while( my $bits = substr $bitstring, -32, 32, '' )
   {
       push @intz, pack $pack_format, $bits;
   }

that or

   my $bits = substr $bitstring, -32, 32, '';

   my $int  = $pack_format, $bits;

   carp "Oversize bitstring: '$bitstring' remaining after $int";

Note that the substr and pack options have to be
consistent with the storage on the architecture
you are using (low- or high-endian) or you have
to force the bits into network order before making
the bitstring.


--
Steven Lembark                                       85-09 90th Street
Workhorse Computing                                Woodhaven, NY 11421
[EMAIL PROTECTED]                                     1 888 359 3508