Recipe 2.15. Converting Binary, Octal, and Hexadecimal Numbers

2.15.1. Problem

You want to convert a string (e.g., "0b10110", "0x55", or "0755") containing a binary, octal, or hexadecimal number to the correct number.

Perl understands numbers specified in binary (base-2), octal (base-8), and hexadecimal (base-16) notation only when they occur as literals in your programs. If they come in as data—such as by reading from files or environment variables, or when supplied as command-line arguments—no automatic conversion takes place.