Binary Math?

[Anonymous Monk]

Are there built in functions (or a module) to provide facilities for simple binary math (eg, accepting two strings representing bitstrings as arguments and returning a bitstring with the result of addition/subtraction) ?

[BrowserUk]

I'm not aware of any modules for this, but I never looked as perl makes it so easy to this yourself.

#! perl -slw
use strict;

sub b2n{ eval '0b'. $_[0] }
sub n2b{ sprintf '%b', $_[0] }


my( $bs1, $bs2 ) = ( '0100100100101', '1010101010100' );

print "$bs1 + $bs2 = ", n2b( b2n( $bs1 ) + b2n( $bs2 ) );

__END__
P:\test>295453
0100100100101 + 1010101010100 = 1111001111001

If your bitstrings are longer than 32 bits (or 64 if your lucky enough to be using a 64-bit platform) then you might need something more elaborate.

[athomason]

Use oct to go from bitstrings to numbers and sprintf to go from a number to a bitstring. As for the math, the usual operators work once you've done the conversion.

#!/usr/bin/perl

use strict;
use warnings;

my $bitstring1 = shift @ARGV || '10010010111';
my $bitstring2 = shift @ARGV || '01101011010';

my $number1 = oct "0b$bitstring1";
my $number2 = oct "0b$bitstring2";

printf "%s + %s = %b\n", $bitstring1, $bitstring2, $number1 + $number2
+;

Update

As BrowserUK mentioned, this will only get you as far as your platform's integer types allow. Fortunately, Math::BigInt also accepts the '0b' prefix for input and has the as_bin method for output, and has replacements for oodles of math operations.

[BUU]

Uh, are you looking for the binary operators  | & ^ defined in perlop?