How do I convert a binary string to a number in Perl?

Question

How can I convert the binary string $x_bin="0001001100101" to its numeric value $x_num=613 in Perl?

Answer 1

My preferred way is:

$x_num = oct("0b" . $x_bin); 

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Quoting from man perlfunc:

     oct EXPR     oct     Interprets EXPR as an octal string and returns the             corresponding value. (If EXPR happens to start             off with "0x", interprets it as a hex string. If             EXPR starts off with "0b", it is interpreted as a             binary string. Leading whitespace is ignored in             all three cases.) 

Answer 2

sub bin2dec {     return unpack("N", pack("B32", substr("0" x 32 . shift, -32))); } 

Answer 3

As usual, there's is also an excellent CPAN module that should be mentioned here: Bit::Vector.

The transformation would look something like this:

use Bit::Vector;

my $v = Bit::Vector->new_Bin( 32, '0001001100101' );
print "hex: ", $v->to_Hex(), "\n";
print "dec: ", $v->to_Dec(), "\n";

The binary strings can be of almost any length and you can do other neat stuff like bit-shifting, etc.