PHPですべてのタイプのスマートクォートを変換する

以下のコード行を使用できます。UTF-8入力が必要です。

$chr_map = array(
   // Windows codepage 1252
   "\xC2\x82" => "'", // U+0082⇒U+201A single low-9 quotation mark
   "\xC2\x84" => '"', // U+0084⇒U+201E double low-9 quotation mark
   "\xC2\x8B" => "'", // U+008B⇒U+2039 single left-pointing angle quotation mark
   "\xC2\x91" => "'", // U+0091⇒U+2018 left single quotation mark
   "\xC2\x92" => "'", // U+0092⇒U+2019 right single quotation mark
   "\xC2\x93" => '"', // U+0093⇒U+201C left double quotation mark
   "\xC2\x94" => '"', // U+0094⇒U+201D right double quotation mark
   "\xC2\x9B" => "'", // U+009B⇒U+203A single right-pointing angle quotation mark
   // Regular Unicode // U+0022 quotation mark (")
   // U+0027 apostrophe (')
   "\xC2\xAB" => '"', // U+00AB left-pointing double angle quotation mark
   "\xC2\xBB" => '"', // U+00BB right-pointing double angle quotation mark
   "\xE2\x80\x98" => "'", // U+2018 left single quotation mark
   "\xE2\x80\x99" => "'", // U+2019 right single quotation mark
   "\xE2\x80\x9A" => "'", // U+201A single low-9 quotation mark
   "\xE2\x80\x9B" => "'", // U+201B single high-reversed-9 quotation mark
   "\xE2\x80\x9C" => '"', // U+201C left double quotation mark
   "\xE2\x80\x9D" => '"', // U+201D right double quotation mark
   "\xE2\x80\x9E" => '"', // U+201E double low-9 quotation mark
   "\xE2\x80\x9F" => '"', // U+201F double high-reversed-9 quotation mark
   "\xE2\x80\xB9" => "'", // U+2039 single left-pointing angle quotation mark
   "\xE2\x80\xBA" => "'", // U+203A single right-pointing angle quotation mark
);
$char_val = array_keys ($chr_map); // but: for efficiency you should
$rpl = array_values($chr_map); // pre-calculate these two arrays
$str = str_replace($char_val, $rpl, html_entity_decode($str, ENT_QUOTES, "UTF-8"));

説明

すべてのUnicode文字は、正確に1つの「一般カテゴリ」に属します。

これらのうち、引用文字を含めることができるのは-

Ps "Punctuation, Open"
Pe "Punctuation, Close"
Pi "Punctuation, Initial quote (might behave like Ps or Pe depending on its usage)"
Pf "Punctuation, Final quote (might behave like Ps or Pe depending on its usage)"
Po "Punctuation, Other"

ユーザーが入力がUTF-8でエンコードされているかどうかわからない場合は、他の操作を実行する前に以下のコードを配置できます-

if ( !preg_match('/^\\X*$/u', $str)) {
   $str = utf8_encode($str);
}

データを0x80-0x9Fの範囲で正規化する必要がある場合は、以下のコードを使用できます-

$normalization_map = array(
   "\xC2\x80" => "\xE2\x82\xAC", // U+20AC Euro sign
   "\xC2\x82" => "\xE2\x80\x9A", // U+201A single low-9 quotation mark
   "\xC2\x83" => "\xC6\x92", // U+0192 latin small letter f with hook
   "\xC2\x84" => "\xE2\x80\x9E", // U+201E double low-9 quotation mark
   "\xC2\x85" => "\xE2\x80\xA6", // U+2026 horizontal ellipsis
   "\xC2\x86" => "\xE2\x80\xA0", // U+2020 dagger
   "\xC2\x87" => "\xE2\x80\xA1", // U+2021 double dagger
   "\xC2\x88" => "\xCB\x86", // U+02C6 modifier letter circumflex accent
   "\xC2\x89" => "\xE2\x80\xB0", // U+2030 per mille sign
   "\xC2\x8A" => "\xC5\xA0", // U+0160 latin capital letter s with caron
   "\xC2\x8B" => "\xE2\x80\xB9", // U+2039 single left-pointing angle quotation mark
   "\xC2\x8C" => "\xC5\x92", // U+0152 latin capital ligature oe
   "\xC2\x8E" => "\xC5\xBD", // U+017D latin capital letter z with caron
   "\xC2\x91" => "\xE2\x80\x98", // U+2018 left single quotation mark
   "\xC2\x92" => "\xE2\x80\x99", // U+2019 right single quotation mark
   "\xC2\x93" => "\xE2\x80\x9C", // U+201C left double quotation mark
   "\xC2\x94" => "\xE2\x80\x9D", // U+201D right double quotation mark
   "\xC2\x95" => "\xE2\x80\xA2", // U+2022 bullet
   "\xC2\x96" => "\xE2\x80\x93", // U+2013 en dash
   "\xC2\x97" => "\xE2\x80\x94", // U+2014 em dash
   "\xC2\x98" => "\xCB\x9C", // U+02DC small tilde
   "\xC2\x99" => "\xE2\x84\xA2", // U+2122 trade mark sign
   "\xC2\x9A" => "\xC5\xA1", // U+0161 latin small letter s with caron
   "\xC2\x9B" => "\xE2\x80\xBA", // U+203A single right-pointing angle quotation mark
   "\xC2\x9C" => "\xC5\x93", // U+0153 latin small ligature oe
   "\xC2\x9E" => "\xC5\xBE", // U+017E latin small letter z with caron
   "\xC2\x9F" => "\xC5\xB8", // U+0178 latin capital letter y with diaeresis
);
$chr = array_keys ($normalization_map); // but: for efficiency you should
$rpl = array_values($normalization_map); // pre-calculate these two arrays
$str = str_replace($chr, $rpl, $str);