文件名字符串过滤器

/[^a-z0-9\._-]+/gi

将今天的财务账单转换成today-s-financial-billing

str_file($raw_string, $word_separator, $file_extension, $fallback_name, $length);

2) 或者仅使用过滤器工具而不构建完整的文件名（严格模式 true 不允许在文件名中使用 [] 或 ()）：

str_file_filter($string, $separator, $strict, $length);

3) 这里是这些函数：

// Returns filesystem-safe string after cleaning, filtering, and trimming input
function str_file_filter(
    $str,
    $sep = '_',
    $strict = false,
    $trim = 248) {

    $str = strip_tags(htmlspecialchars_decode(strtolower($str))); // lowercase -> decode -> strip tags
    $str = str_replace("%20", ' ', $str); // convert rogue %20s into spaces
    $str = preg_replace("/%[a-z0-9]{1,2}/i", '', $str); // remove hexy things
    $str = str_replace(" ", ' ', $str); // convert all nbsp into space
    $str = preg_replace("/&#?[a-z0-9]{2,8};/i", '', $str); // remove the other non-tag things
    $str = preg_replace("/\s+/", $sep, $str); // filter multiple spaces
    $str = preg_replace("/\.+/", '.', $str); // filter multiple periods
    $str = preg_replace("/^\.+/", '', $str); // trim leading period

    if ($strict) {
        $str = preg_replace("/([^\w\d\\" . $sep . ".])/", '', $str); // only allow words and digits
    } else {
        $str = preg_replace("/([^\w\d\\" . $sep . "\[\]\(\).])/", '', $str); // allow words, digits, [], and ()
    }

    $str = preg_replace("/\\" . $sep . "+/", $sep, $str); // filter multiple separators
    $str = substr($str, 0, $trim); // trim filename to desired length, note 255 char limit on windows

    return $str;
}


// Returns full file name including fallback and extension
function str_file(
    $str,
    $sep = '_',
    $ext = '',
    $default = '',
    $trim = 248) {

    // Run $str and/or $ext through filters to clean up strings
    $str = str_file_filter($str, $sep);
    $ext = '.' . str_file_filter($ext, '', true);

    // Default file name in case all chars are trimmed from $str, then ensure there is an id at tail
    if (empty($str) && empty($default)) {
        $str = 'no_name__' . date('Y-m-d_H-m_A') . '__' . uniqid();
    } elseif (empty($str)) {
        $str = $default;
    }

    // Return completed string
    if (!empty($ext)) {
        return $str . $ext;
    } else {
        return $str;
    }
}

假设有一些用户输入如下：.....&lt;div&gt;&lt;/div&gt;<script></script>&amp; Weiß Göbel 中文百强网File name %20 %20 %21 %2C Décor \/. /. . z \... y \...... x ./ “This name” is & 462^^ not &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = that grrrreat -][09]()1234747) საბეჭდი-და-ტიპოგრაფიული

我们想将其转换为更友好的格式，以便使用文件名长度为255个字符的tar.gz。以下是一个示例用法。注意：此示例包括一个格式错误的tar.gz扩展名作为概念证明，您仍应根据白名单过滤字符串构建后的扩展名。

$raw_str = '.....&lt;div&gt;&lt;/div&gt;<script></script>&amp; Weiß Göbel 中文百强网File name  %20   %20 %21 %2C Décor  \/.  /. .  z \... y \...... x ./  “This name” is & 462^^ not &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = that grrrreat -][09]()1234747) საბეჭდი-და-ტიპოგრაფიული';
$fallback_str = 'generated_' . date('Y-m-d_H-m_A');
$bad_extension = '....t&+++a()r.gz[]';

echo str_file($raw_str, '_', $bad_extension, $fallback_str);

/**
 * Converts to ASCII.
 * @param  string  UTF-8 encoding
 * @return string  ASCII
 */
public static function toAscii($s)
{
    static $transliterator = NULL;
    if ($transliterator === NULL && class_exists('Transliterator', FALSE)) {
        $transliterator = \Transliterator::create('Any-Latin; Latin-ASCII');
    }

    $s = preg_replace('#[^\x09\x0A\x0D\x20-\x7E\xA0-\x{2FF}\x{370}-\x{10FFFF}]#u', '', $s);
    $s = strtr($s, '`\'"^~?', "\x01\x02\x03\x04\x05\x06");
    $s = str_replace(
        array("\xE2\x80\x9E", "\xE2\x80\x9C", "\xE2\x80\x9D", "\xE2\x80\x9A", "\xE2\x80\x98", "\xE2\x80\x99", "\xC2\xB0"),
        array("\x03", "\x03", "\x03", "\x02", "\x02", "\x02", "\x04"), $s
    );
    if ($transliterator !== NULL) {
        $s = $transliterator->transliterate($s);
    }
    if (ICONV_IMPL === 'glibc') {
        $s = str_replace(
            array("\xC2\xBB", "\xC2\xAB", "\xE2\x80\xA6", "\xE2\x84\xA2", "\xC2\xA9", "\xC2\xAE"),
            array('>>', '<<', '...', 'TM', '(c)', '(R)'), $s
        );
        $s = @iconv('UTF-8', 'WINDOWS-1250//TRANSLIT//IGNORE', $s); // intentionally @
        $s = strtr($s, "\xa5\xa3\xbc\x8c\xa7\x8a\xaa\x8d\x8f\x8e\xaf\xb9\xb3\xbe\x9c\x9a\xba\x9d\x9f\x9e"
            . "\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3"
            . "\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8"
            . "\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf8\xf9\xfa\xfb\xfc\xfd\xfe"
            . "\x96\xa0\x8b\x97\x9b\xa6\xad\xb7",
            'ALLSSSSTZZZallssstzzzRAAAALCCCEEEEIIDDNNOOOOxRUUUUYTsraaaalccceeeeiiddnnooooruuuuyt- <->|-.');
        $s = preg_replace('#[^\x00-\x7F]++#', '', $s);
    } else {
        $s = @iconv('UTF-8', 'ASCII//TRANSLIT//IGNORE', $s); // intentionally @
    }
    $s = str_replace(array('`', "'", '"', '^', '~', '?'), '', $s);
    return strtr($s, "\x01\x02\x03\x04\x05\x06", '`\'"^~?');
}


/**
 * Converts to web safe characters [a-z0-9-] text.
 * @param  string  UTF-8 encoding
 * @param  string  allowed characters
 * @param  bool
 * @return string
 */
public static function webalize($s, $charlist = NULL, $lower = TRUE)
{
    $s = self::toAscii($s);
    if ($lower) {
        $s = strtolower($s);
    }
    $s = preg_replace('#[^a-z0-9' . preg_quote($charlist, '#') . ']+#i', '-', $s);
    $s = trim($s, '-');
    return $s;
}

使用此功能仅接受字符串中的单词（支持Unicode，如UTF-8）、"."、"-"和"_"：

$sanitized = preg_replace('/[^\w\-\._]/u','', $filename);

function sanitize_file_name($file_name) { 
 // case of multiple dots
  $explode_file_name =explode('.', $file_name);
  $extension =array_pop($explode_file_name);
  $file_name_without_ext=substr($file_name, 0, strrpos( $file_name, '.') );    
  // replace special characters
  $file_name_without_ext = preg_quote($file_name_without_ext);
  $file_name_without_ext = preg_replace('/[^a-zA-Z0-9\\_]/', '_', $file_name_without_ext);
  $file_name=$file_name_without_ext . '.' . $extension;    
  return $file_name;
}

用户提供的文件名中的 / 和 .. 可能会对系统造成危害。因此，您应该采取类似以下方式来消除它们：

$fname = str_replace('..', '', $fname);
$fname = str_replace('/',  '', $fname);

一种方法

$bad='/[\/:*?"<>|]/';
$string = 'fi?le*';

function sanitize($str,$pat)
{
    return preg_replace($pat,"",$str);

}
echo sanitize($string,$bad);

$fname = str_replace('/','',$fname);

由于用户可能使用斜杠来分隔两个单词，最好将其替换为破折号而不是 NULL。