Write a Binary to Decimal Perl program. Make sure to use very low-level knowledge to solve this, please.

Don't use the pack / unpack functions of Perl.

Input an integer containing only the digits 0 and 1 (i.e., a binary number) and print its decimal equivalent.

The program should be able to handle input from 1 to 30 digits. We do not need to check the input string for validity (i.e, if all characters entered are 0 s or 1 s); we can assume that the data will be valid.

All input will consist of 0 s and 1 s and will be 1 or more characters long but not longer than 30 characters.

Sample run 1:

Please enter a binary number up to 30 digits: 11111111111

11111111111 is 2047 in decimal.

2:

Please enter a binary number up to 30 digits: 11111111111111111111

11111111111111111111 is 1048575 in decimal.

3:

Please enter a binary number up to 30 digits: 00000000000000000001

00000000000000000001 is 1 in decimal.

4:

Please enter a binary number up to 30 digits: 1

1 is 1 in decimal.

5:

Please enter a binary number up to 30 digits: 10101010101010101010

10101010101010101010 is 699050 in decimal.

6:

Please enter a binary number up to 30 digits: 111111111111111111111111111111

111111111111111111111111111111 is 1073741823 in decimal.

7:

Please enter a binary number up to 30 digits: 111111111111111111111111111110

111111111111111111111111111110 is 1073741822 in decimal.