crc32算法php版----crc32.php

<?php$remainder = (int)0xFFFFFFFF;
$poly=(int)0x04C11DB7;//$stringArray = array(0x68, 0x65);
$stringArray = array("h","e");//$string = "h";
//$hex = bin2hex($string);
//echo $hex; // 输出: 68
//$string = "h";
//$hex = ord($string);
//echo $hex; // 输出: 104!!!function reverseBits($n) {$result = $n & 0xff;//echo "<br> reverseBits \$n= ".$result."<br>";$result2=0x0 & 0xff;for ($i = 0; $i < 8; $i++) {$result1 = ($result2 << 1) &0xff;//echo "<br> result1= ".$result1."<br>";    $n1=$n & 1<<$i;if($n1 !=0x0){$n2=0x1;}else {$n2=0x0;}//echo "<br> n2= ".$n2."<br>";$result2 = $result1 | $n2;//echo "<br> == ".$result2."<br>";}//echo "<br> reverseBits == ".$result2."<br>";return $result2;
}//echo dechex(reverseBits(0x68));
//echo dechex(reverseBits(bin2hex("h")));
//echo dechex(reverseBits(ord("h")));function reverseBits32($n) {$result = $n & 0xffffffff;//echo "<br> reverseBits \$n= ".dechex($result)."<br>";for ($i = 0; $i < 32; $i++) {$result1 = ($result2 << 1) &0xffffffff;//echo "<br> result1= ".$result1."<br>";    $n1=($n & 1<<$i) & 0xffffffffff;if($n1 !=0x0){$n2=0x1;}else {$n2=0x0;    // code...}//echo "<br> n2= ".$n2."<br>";$result2 = $result1 | $n2;//echo "<br> = ".$result2."<br>";}return $result2;
}
//echo "<br> reverseBits32==== ".dechex(reverseBits32(0x68000000));foreach ($stringArray as $string) {//echo "<br>\$string".$string . "<br>";$stringhex= reverseBits(ord($string));//echo "<br> reverseBits ==== ".$stringhex;//echo "<br> \$stringhexx = ".dechex($stringhexx). "<br>";$stringhexx= ($stringhex << 24) & 0xFFFFFFFF; $remainder = ($remainder^$stringhexx)& 0xFFFFFFFF;//echo "<br>".dechex($remainder) . "<br>";for($i=0;$i<8;$i++)  {//echo "<br> for begin \$remainder= ".dechex($remainder) . "<br>";if ($remainder & 0x80000000){$remainder = ($remainder << 1 ) & 0xFFFFFFFF;//echo "<br> for if 1 <<1 =  ".dechex($remainder) . "<br>";$remainder =($remainder ^ $poly)& 0xFFFFFFFF;//echo "<br> for if 1 =".dechex($remainder) . "<br>";}else{$remainder = ($remainder << 1 ) & 0xFFFFFFFF;//echo "<br> for if 2 <<1 =".dechex($remainder) . "<br>";        }}echo "<br>\$string =".$string . "<br>"; $remainder= reverseBits32($remainder);//echo "<br>".$remainder;
//echo "<br> not xor= ".dechex($remainder);$remainder=($remainder^0xFFFFFFFF);echo "<br> xor =".dechex($remainder);
}echo "<br>========".dechex($remainder); ?>

<?php
echo "<br>";
$str1 = crc32("h");
printf("crc32(\"h\")=%8x",$str1);
echo "<br>";
$str2 = crc32("he");
printf("crc32(\"he\")=%8x ",$str2);//jieguo:
?>

crc32("h")=916b06e7
crc32("he")=d1256687