1<?php
2
3namespace dokuwiki\Utf8;
4
5/**
6 * Methods to assess and clean UTF-8 strings
7 */
8class Clean
9{
10    /**
11     * Checks if a string contains 7bit ASCII only
12     *
13     * @author Andreas Haerter <andreas.haerter@dev.mail-node.com>
14     *
15     * @param string $str
16     * @return bool
17     */
18    public static function isASCII($str)
19    {
20        return (preg_match('/(?:[^\x00-\x7F])/', $str) !== 1);
21    }
22
23    /**
24     * Tries to detect if a string is in Unicode encoding
25     *
26     * @author <bmorel@ssi.fr>
27     * @link   http://php.net/manual/en/function.utf8-encode.php
28     *
29     * @param string $str
30     * @return bool
31     */
32    public static function isUtf8($str)
33    {
34        $len = strlen($str);
35        for ($i = 0; $i < $len; $i++) {
36            $b = ord($str[$i]);
37            if ($b < 0x80) continue; # 0bbbbbbb
38            elseif (($b & 0xE0) === 0xC0) $n = 1; # 110bbbbb
39            elseif (($b & 0xF0) === 0xE0) $n = 2; # 1110bbbb
40            elseif (($b & 0xF8) === 0xF0) $n = 3; # 11110bbb
41            elseif (($b & 0xFC) === 0xF8) $n = 4; # 111110bb
42            elseif (($b & 0xFE) === 0xFC) $n = 5; # 1111110b
43            else return false; # Does not match any model
44
45            for ($j = 0; $j < $n; $j++) { # n bytes matching 10bbbbbb follow ?
46                if ((++$i === $len) || ((ord($str[$i]) & 0xC0) !== 0x80))
47                    return false;
48            }
49        }
50        return true;
51    }
52
53    /**
54     * Strips all high byte chars
55     *
56     * Returns a pure ASCII7 string
57     *
58     * @author Andreas Gohr <andi@splitbrain.org>
59     *
60     * @param string $str
61     * @return string
62     */
63    public static function strip($str)
64    {
65        $ascii = '';
66        $len = strlen($str);
67        for ($i = 0; $i < $len; $i++) {
68            if (ord($str[$i]) < 128) {
69                $ascii .= $str[$i];
70            }
71        }
72        return $ascii;
73    }
74
75    /**
76     * Removes special characters (nonalphanumeric) from a UTF-8 string
77     *
78     * This function adds the controlchars 0x00 to 0x19 to the array of
79     * stripped chars (they are not included in $UTF8_SPECIAL_CHARS)
80     *
81     * @author Andreas Gohr <andi@splitbrain.org>
82     *
83     * @param  string $string The UTF8 string to strip of special chars
84     * @param  string $repl Replace special with this string
85     * @param  string $additional Additional chars to strip (used in regexp char class)
86     * @return string
87     */
88    public static function stripspecials($string, $repl = '', $additional = '')
89    {
90        static $specials = null;
91        if ($specials === null) {
92            $specials = preg_quote(Table::specialChars(), '/');
93        }
94
95        return preg_replace('/[' . $additional . '\x00-\x19' . $specials . ']/u', $repl, $string);
96    }
97
98    /**
99     * Replace bad bytes with an alternative character
100     *
101     * ASCII character is recommended for replacement char
102     *
103     * PCRE Pattern to locate bad bytes in a UTF-8 string
104     * Comes from W3 FAQ: Multilingual Forms
105     * Note: modified to include full ASCII range including control chars
106     *
107     * @author Harry Fuecks <hfuecks@gmail.com>
108     * @see http://www.w3.org/International/questions/qa-forms-utf-8
109     *
110     * @param string $str to search
111     * @param string $replace to replace bad bytes with (defaults to '?') - use ASCII
112     * @return string
113     */
114    public static function replaceBadBytes($str, $replace = '')
115    {
116        $UTF8_BAD =
117            '([\x00-\x7F]' .                          # ASCII (including control chars)
118            '|[\xC2-\xDF][\x80-\xBF]' .               # non-overlong 2-byte
119            '|\xE0[\xA0-\xBF][\x80-\xBF]' .           # excluding overlongs
120            '|[\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}' .    # straight 3-byte
121            '|\xED[\x80-\x9F][\x80-\xBF]' .           # excluding surrogates
122            '|\xF0[\x90-\xBF][\x80-\xBF]{2}' .        # planes 1-3
123            '|[\xF1-\xF3][\x80-\xBF]{3}' .            # planes 4-15
124            '|\xF4[\x80-\x8F][\x80-\xBF]{2}' .        # plane 16
125            '|(.{1}))';                               # invalid byte
126        ob_start();
127        while (preg_match('/' . $UTF8_BAD . '/S', $str, $matches)) {
128            if (!isset($matches[2])) {
129                echo $matches[0];
130            } else {
131                echo $replace;
132            }
133            $str = substr($str, strlen($matches[0]));
134        }
135        return ob_get_clean();
136    }
137
138
139    /**
140     * Replace accented UTF-8 characters by unaccented ASCII-7 equivalents
141     *
142     * Use the optional parameter to just deaccent lower ($case = -1) or upper ($case = 1)
143     * letters. Default is to deaccent both cases ($case = 0)
144     *
145     * @author Andreas Gohr <andi@splitbrain.org>
146     *
147     * @param string $string
148     * @param int $case
149     * @return string
150     */
151    public static function deaccent($string, $case = 0)
152    {
153        if ($case <= 0) {
154            $string = strtr($string, Table::lowerAccents());
155        }
156        if ($case >= 0) {
157            $string = strtr($string, Table::upperAccents());
158        }
159        return $string;
160    }
161
162    /**
163     * Romanize a non-latin string
164     *
165     * @author Andreas Gohr <andi@splitbrain.org>
166     *
167     * @param string $string
168     * @return string
169     */
170    public static function romanize($string)
171    {
172        if (self::isASCII($string)) return $string; //nothing to do
173
174        return strtr($string, Table::romanization());
175    }
176
177    /**
178     * adjust a byte index into a utf8 string to a utf8 character boundary
179     *
180     * @author       chris smith <chris@jalakai.co.uk>
181     *
182     * @param string $str utf8 character string
183     * @param int $i byte index into $str
184     * @param bool $next direction to search for boundary, false = up (current character) true = down (next character)
185     * @return int byte index into $str now pointing to a utf8 character boundary
186     */
187    public static function correctIdx($str, $i, $next = false)
188    {
189
190        if ($i <= 0) return 0;
191
192        $limit = strlen($str);
193        if ($i >= $limit) return $limit;
194
195        if ($next) {
196            while (($i < $limit) && ((ord($str[$i]) & 0xC0) === 0x80)) $i++;
197        } else {
198            while ($i && ((ord($str[$i]) & 0xC0) === 0x80)) $i--;
199        }
200
201        return $i;
202    }
203}
204