PHP 将字符串转换为十六进制以及十六进制转换为字符串

Question

在 PHP 中这两种类型之间转换时遇到问题。这是我在google上搜索到的代码

function strToHex($string){
    $hex='';
    for ($i=0; $i < strlen($string); $i++){
        $hex .= dechex(ord($string[$i]));
    }
    return $hex;
}


function hexToStr($hex){
    $string='';
    for ($i=0; $i < strlen($hex)-1; $i+=2){
        $string .= chr(hexdec($hex[$i].$hex[$i+1]));
    }
    return $string;
}

我检查了一下，在使用XOR加密时发现了这一点。

我有字符串

"this is the test"

，与密钥进行异或后，结果在字符串

↕↑↔§P↔§P ♫§T↕§↕

中。之后，我尝试通过函数 strToHex() 将其转换为十六进制，并得到了这些

12181d15501d15500e15541215712

。然后，我用函数 hexToStr() 进行了测试，结果是

↕↑↔§P↔§P♫§T↕§q

。那么，我应该怎么做才能解决这个问题呢？为什么我转换这2个样式值时会出错？

Answer 1

对于最终来到这里并且只是寻找（二进制）字符串的十六进制表示形式的人。

bin2hex("that's all you need");
# 74686174277320616c6c20796f75206e656564

hex2bin('74686174277320616c6c20796f75206e656564');
# that's all you need

文档：bin2hex，hex2bin。

Answer 2

对于任何带有 ord($char) 的字符 < 16 you get a HEX back which is only 1 long. You forgot to add 0 padding.

这应该可以解决问题：

<?php
function strToHex($string){
    $hex = '';
    for ($i=0; $i<strlen($string); $i++){
        $ord = ord($string[$i]);
        $hexCode = dechex($ord);
        $hex .= substr('0'.$hexCode, -2);
    }
    return strToUpper($hex);
}
function hexToStr($hex){
    $string='';
    for ($i=0; $i < strlen($hex)-1; $i+=2){
        $string .= chr(hexdec($hex[$i].$hex[$i+1]));
    }
    return $string;
}


// Tests
header('Content-Type: text/plain');
function test($expected, $actual, $success) {
    if($expected !== $actual) {
        echo "Expected: '$expected'\n";
        echo "Actual:   '$actual'\n";
        echo "\n";
        $success = false;
    }
    return $success;
}

$success = true;
$success = test('00', strToHex(hexToStr('00')), $success);
$success = test('FF', strToHex(hexToStr('FF')), $success);
$success = test('000102FF', strToHex(hexToStr('000102FF')), $success);
$success = test('↕↑↔§P↔§P ♫§T↕§↕', hexToStr(strToHex('↕↑↔§P↔§P ♫§T↕§↕')), $success);

echo $success ? "Success" : "\nFailed";

Answer 3

PHP：

字符串转十六进制：

implode(unpack("H*", $string));

十六进制到字符串：

pack("H*", $hex);

Answer 4

这是我使用的：

function strhex($string) {
  $hexstr = unpack('H*', $string);
  return array_shift($hexstr);
}

Answer 5

function hexToStr($hex){
    // Remove spaces if the hex string has spaces
    $hex = str_replace(' ', '', $hex);
    return hex2bin($hex);
}
// Test it 
$hex    = "53 44 43 30 30 32 30 30 30 31 37 33";
echo hexToStr($hex); // SDC002000173

/**
 * Test Hex To string with PHP UNIT
 * @param  string $value
 * @return 
 */
public function testHexToString()
{
    $string = 'SDC002000173';
    $hex    = "53 44 43 30 30 32 30 30 30 31 37 33";
    $result = hexToStr($hex);

    $this->assertEquals($result,$string);
}

Answer 6

使用@bill-shirley 答案并添加一点

function str_to_hex($string) {
$hexstr = unpack('H*', $string);
return array_shift($hexstr);
}
function hex_to_str($string) {
return hex2bin("$string");
}

用途：

  $str = "Go placidly amidst the noise";
  $hexstr = str_to_hex($str);// 476f20706c616369646c7920616d6964737420746865206e6f697365
  $strstr = hex_to_str($str);// Go placidly amidst the noise

Answer 7

您可以尝试以下代码将图像转换为十六进制字符串

<?php
$image = 'sample.bmp';
$file = fopen($image, 'r') or die("Could not open $image");
while ($file && !feof($file)){
$chunk = fread($file, 1000000); # You can affect performance altering
this number. YMMV.
# This loop will be dog-slow, almost for sure...
# You could snag two or three bytes and shift/add them,
# but at 4 bytes, you violate the 7fffffff limit of dechex...
# You could maybe write a better dechex that would accept multiple bytes
# and use substr... Maybe.
for ($byte = 0; $byte < strlen($chunk); $byte++)){
echo dechex(ord($chunk[$byte]));
}
}
?>

Answer 8

我只有一半的答案，但我希望它有用，因为它添加了 unicode (utf-8) 支持

    /**
     * hexadecimal to unicode character
     * @param  string  $hex
     * @return string
     */
    function hex2uni($hex) { 
      $dec = hexdec($hex);
        if($dec < 128) {
            return chr($dec);
        }
        if($dec < 2048) {
            $utf = chr(192 + (($dec - ($dec % 64)) / 64));
        } else {
            $utf = chr(224 + (($dec - ($dec % 4096)) / 4096));
            $utf .= chr(128 + ((($dec % 4096) - ($dec % 64)) / 64));
        }
        return $utf . chr(128 + ($dec % 64));
    }

串起来

    var_dump(hex2uni('e641'));

基于：http://www.php.net/manual/en/function.chr.php#Hcom55978

Answer 9

以下是将十六进制转换为字符串的方法：

    $s = '\x64\x65';
    $t = array_map(function($item){
        return pack("H*", $item);
    }, explode('/x', $s));
    $result = implode('', $t);