<?
/****************************************
convertBase($number, $originalBase, $destinationBase);

Author: Chris Heald
Email: cheald45@hotmail.com
Creation date: 1/16/02

License: No restriction, provided this header is left intact. You may
change the purpose if you update the code - leave the author, email,
creation date, license, and changelog intact. You may append to the
changelog as you make changes.

Purpose:
Use to convert a number in any base from 2 to 36 to any other base from 2 to 36.
ie: convertBase("FF",16,10) returns 255. You can also use HEX, BINARY, BASE10, DECIMAL and OCT in place of numeric
values for the bases. ie: convertBase("FF",HEX,BINARY) returns 11111111.

HEX    : 16
BASE10 : 10
DECIMAL: 10
OCT    :  8
BINARY :  2

Possible future enhancements:
Even more bases supported. We could use lower case and upper case letters as seperate digits, but that could get
confusing. The benefit of this would be a maximum range of 62 bases.

This was an exericse I did in my free time. Please feel free
to expand or enhance it, and feel free to email me if you have questions.

*** Change Log ***
01/16/02 - CMH
Created File. Version 1.00
******************
****************************************/

define("HEX",16);
define("BINARY",2);
define("OCT",8);
define("BASE10",10);
define("DECIMAL", 10);
function convertBase($number, $fromBase = 10, $toBase = 2) {

        if($toBase > 36 || $toBase < 2)			//check base validity
        return "Invalid originating base.";
        if($fromBase > 36 || $fromBase < 2)
        return "Invalid destination base.";

        @list($number, $decimal) = explode(".",$number);
        for($i = 0; $i < strlen($number); $i++) {		//convert to base 10
                $digit = substr($number, $i, 1);
                if(eregi("[a-z]",$digit)) {
                        $x = ord($digit) - 65 + 10;
                        if($x > $fromBase)
                        $x -= 32;
                        $digit = $x;
                }
                @$base10 += $digit * (pow($fromBase, strlen($number) - $i - 1));
        }
        $number = $base10;
        if($toBase == 10)
        return $number;
        $q = $number;
        while($q != 0) {		//convert base 10 equivalent to specified base
                $r = $q % $toBase;
                $q = floor($q / $toBase);
                if($r > 9)
                $r = chr(($r - 9) + 64);
                @$baseres = "$r" . "$baseres";
        }
        return $baseres;
}

?>