Using big numbers in Perl - perl

Question

I have a scenario where I take 2 very big binary strings (having 100 characters) and I need to add them.
The issue is that I am getting the answer in the form 2.000xxxxxxxxxxe+2, whereas I need the precise answer, as another 100 character long string.
chomp($str1=<STDIN>);
chomp($str2=<STDIN>);
print "Str 1 is $str1\n";
print "Str 2 is $str2\n";
$t = $str1 + $str2;
print "Sum is $t\n";
Sample Input
1001101111101011011100101100100110111011111011000100111100111110111101011011011100111001100011111010
1001101111101011011100101100100110111011111011000100111100111110111101011011011100111001100011111010
Sample Output
Str1 is
1001101111101011011100101100100110111011111011000100111100111110111101011011011100111001100011111010
Str2 is
1001101111101011011100101100100110111011111011000100111100111110111101011011011100111001100011111010
Sum is
2.0022022220202e+099

Answer 1

As already suggested, you can use Math::BigInt core module,
use Math::BigInt;
# chomp($str1=<STDIN>);
# chomp($str2=<STDIN>);
# print "Str 1 is $str1\n";
# print "Str 2 is $str2\n";
my $t = Math::BigInt->new("0b$str1") + Math::BigInt->new("0b$str2");
print $t->as_bin;

Answer 2

In order to perform arithmetic on your strings, Perl converts them to floating-point numbers, which are inherently imprecise. If you want to avoid that, use Math::BigInt as already suggested ... or roll your own.
######## WARNING/GUARANTEE: This is practically certain to be
# slower, buggier, less portable, and less secure than Math::BigInt.
# In fact, I planted a security hole just to prove a point. Enjoy.
use strict;
use warnings;
sub addition {
my ($int1, $int2) = #_;
my #int1 = reverse split //, $int1;
my #int2 = reverse split //, $int2;
my $len = scalar(#int1>#int2 ? #int1 : #int2);
my #result;
my $carry = 0;
for (my $i=0; $i < $len; ++$i)
{
$int1[$i] |= 0;
$int2[$i] |= 0;
my $sum = $carry + $int1[$i] + $int2[$i];
if ($sum >= 10)
{
$carry = int($sum / 10);
$sum %= 10;
}
push #result, $sum;
}
push #result, $carry if $carry;
return join ('', reverse #result);
}