64和10进制的相互转换-PHP实现

来源：互联网发布：nginx 新增模块编辑：程序博客网时间：2024/06/05 20:55
function b64dec($b64) { //64进制转换成10进制    $map = array(        '0'=>0,'1'=>1,'2'=>2,'3'=>3,'4'=>4,'5'=>5,'6'=>6,'7'=>7,'8'=>8,'9'=>9,        'A'=>10,'B'=>11,'C'=>12,'D'=>13,'E'=>14,'F'=>15,'G'=>16,'H'=>17,'I'=>18,'J'=>19,        'K'=>20,'L'=>21,'M'=>22,'N'=>23,'O'=>24,'P'=>25,'Q'=>26,'R'=>27,'S'=>28,'T'=>29,        'U'=>30,'V'=>31,'W'=>32,'X'=>33,'Y'=>34,'Z'=>35,'a'=>36,'b'=>37,'c'=>38,'d'=>39,        'e'=>40,'f'=>41,'g'=>42,'h'=>43,'i'=>44,'j'=>45,'k'=>46,'l'=>47,'m'=>48,'n'=>49,        'o'=>50,'p'=>51,'q'=>52,'r'=>53,'s'=>54,'t'=>55,'u'=>56,'v'=>57,'w'=>58,'x'=>59,        'y'=>60,'z'=>61,'_'=>62,'='=>63    );    $dec = 0;    $len = strlen($b64);    for ($i = 0; $i < $len; $i++) {        $b = $map[$b64{$i}];        if ($b === NULL) {            return FALSE;        }        $j = $len - $i - 1;        $dec += ($j == 0 ? $b : (2 << (6 * $j - 1)) * $b);    }    return $dec;}function decb64($dec) { //10进制转换成64进制    if ($dec < 0) {        return FALSE;    }    $map = array(        0=>'0',1=>'1',2=>'2',3=>'3',4=>'4',5=>'5',6=>'6',7=>'7',8=>'8',9=>'9',        10=>'A',11=>'B',12=>'C',13=>'D',14=>'E',15=>'F',16=>'G',17=>'H',18=>'I',19=>'J',        20=>'K',21=>'L',22=>'M',23=>'N',24=>'O',25=>'P',26=>'Q',27=>'R',28=>'S',29=>'T',        30=>'U',31=>'V',32=>'W',33=>'X',34=>'Y',35=>'Z',36=>'a',37=>'b',38=>'c',39=>'d',        40=>'e',41=>'f',42=>'g',43=>'h',44=>'i',45=>'j',46=>'k',47=>'l',48=>'m',49=>'n',        50=>'o',51=>'p',52=>'q',53=>'r',54=>'s',55=>'t',56=>'u',57=>'v',58=>'w',59=>'x',        60=>'y',61=>'z',62=>'_',63=>'=',    );    $b64 = '';    do {        $b64 = $map[($dec % 64)] . $b64;        $dec /= 64;    } while ($dec >= 1);    return $b64;}
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