Php string replace utf 8 characters

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

mb_ereg_replace — Replace regular expression with multibyte support

Description

mb_ereg_replace(
    string $pattern,
    string $replacement,
    string $string,
    ?string $options = null
): string|false|null

Scans string for matches to pattern, then replaces the matched text with replacement

Parameters

The regular expression pattern.

Multibyte characters may be used in pattern.

The replacement text.

The string being checked.

Return Values

The resultant string on success, or false on error. If string is not valid for the current encoding, null is returned.

Changelog

Notes

Note:

The internal encoding or the character encoding specified by mb_regex_encoding() will be used as the character encoding for this function.

Warning

Never use the e modifier when working on untrusted input. No automatic escaping will happen (as known from preg_replace()). Not taking care of this will most likely create remote code execution vulnerabilities in your application.

See Also

• mb_regex_encoding() - Set/Get character encoding for multibyte regex
• mb_eregi_replace() - Replace regular expression with multibyte support ignoring case

Pluche ¶

11 years ago

Unlike preg_replace, mb_ereg_replace doesn't use separators

Exemple with preg_replace :
= preg_replace("/[^A-Za-z0-9\.\-]/","",$data); ?>

Exemple with mb_ereg_replace :
= mb_ereg_replace("[^A-Za-z0-9\.\-]","",$data); ?>

daemoneye at gmail dot com ¶

13 years ago

I got a pretty nasty error while trying to parse table rows(all contents were set to UTF-8) from the database for a dictionary project. The idea was to get all the rows from the first table (that is a table with bulgarian phrase in the first field, and its translation in english, french and german in the next fields). I needed to index all the bulgarian words that are found in the table to make an intelligent search. And that is where my headache started.

First of all, even with mb_strtolower() a lot of cyrillic characters went corrupted (ex: 'т,ъ,у,ф,б,г,з,ж,' etc...). After an hour of different attempts I got such a solution:

mb_internal_encoding

Anonymous ¶

6 years ago

Pluche's comment should REALLY be added to the documentation, preferably under the "$pattern" param description. It is crucial to using this function.

trng ¶

11 years ago

You can use \\n for capture group in replacement.
And you can NOT use $n notation (unlike preg_replace function).

keizo at gomo dot jp ¶

14 years ago

$pattern = "([あ-ん]+)[0-9]+";
$string = mb_ereg_replace($pattern, '「\\1」:\\0', $string);
?>

you can use \\n for capture group in replacement

Alexey Khrulev ¶

5 years ago

If encoding of PHP script differs from encoding of string to be processed by mb_ereg_replace(), then you can't just write pattern in script. Both $pattern and $replacement must be converted to same encoding as string to be processed. In this example script is in UTF-8, file to be processed is in UTF-16LE encoding:

$file_encoding = 'UTF-16LE';
mb_regex_encoding( $file_encoding );$pattern     = "aaa";
$replacement = "AAA";
$pattern_encoded     = mb_convert_encoding( $pattern,     $file_encoding, 'UTF-8' );
$replacement_encoded = mb_convert_encoding( $replacement, $file_encoding, 'UTF-8' );$result = mb_ereg_replace( $pattern_encoded, $replacement_encoded, file_get_contents('UTF-16LE.txt') );
file_put_contents('UTF-16LE-updated.txt', $result);
?>

Anonymous ¶

15 years ago

'i' option does not work correctly with multibyte characters. The function does not locate/replace the multibyte string if it's different case then specified on multibyte needle which is in different case.

Anonymous ¶

3 months ago

Notations to reference captures in the replacement string:

// (1) \\number notation: (1 to 9, not greater than 9)
echo mb_ereg_replace('(\S*) (\S*) (\S*)', '\\1 jam, \\2 juice, \\3 squash', 'apple orange lemon').'
'; // apple jam, orange juice, lemon squash

// (2) \k notation: (also greater than 9) (also as \k'number')

j-fr dot fortier at wanadoo dot fr ¶

3 years ago

Since PHP 5.4, to make uppercase ou lowercase characters, or rewrite some uris, without to take care about initial encoding, the transliteration is easier (and probably the best way): see http://php.net/manual/fr/transliterator.transliterate.php and http://userguide.icu-project.org/transforms/general

For example (with create) (french text: replace all accuentued -éèàîïùç...- chars with ascii chars):
$transliterator = Transliterator::create("NFD; [:Nonspacing Mark:] Remove; NFC;");
echo $transliterator->transliterate("Héhé, ça marche !");
?>
// Result: « Hehe, ca marche ! »

To rewrite a phrase in URI (with createFromRules):
$transliterator = Transliterator::createFromRules("::Latin-ASCII; ::Lower; [^[:L:][:N:]]+ > '-';");
echo trim($transliterator->transliterate("Héhé, ça marche !"), '-');
?>
// Result : « hehe-ca-marche »

vondrej(at)gmail(dot)com ¶

16 years ago

Are you looking for htmlentities() for multibyte strings? This might help you - it just replace <, >, ", '

/**
*  Multibyte equivalent for htmlentities() [lite version :)]
*
* @param string $str
* @param string $encoding
* @return string
**/
function mb_htmlentities($str, $encoding = 'utf-8') {
    mb_regex_encoding($encoding);
    $pattern = array('<', '>', '"', '\'');
    $replacement = array('<', '>', '"', ''');
    for ($i=0; $i<sizeof($pattern); $i++) {
        $str = mb_ereg_replace($pattern[$i], $replacement[$i], $str);
    }
    return $str;
}
?>

gmx dot net at ulrich dot mierendorff ¶

14 years ago

If you want to replace characters like "ä" or "ø" you can use mb_ereg_replace, but it is very slow. str_replace is much faster and also works with characters like "ä" or "ø"!

I think this has something to with the fact that str_replace works on byte level and does not care about characters.
I hope that can help.

faxe at neostrada dot pl ¶

17 years ago

A simple mb_str_ireplace() implementation - a faster (?) replacement for non-regexp multi-byte string replacement:

function mb_str_ireplace($co, $naCo, $wCzym)
{
    $wCzymM = mb_strtolower($wCzym);
    $coM    = mb_strtolower($co);
    $offset = 0;

            while(!

marco at thenetworksolution dot it ¶

8 years ago

To selectively uppercase parts of a string via mb_eregi_replace

    $str = mb_eregi_replace('\b([0-9]{1,4}[a-z]{1,2})\b', "strtoupper
('\\1')", $str, 'e');

Full example, how to fix an address manually typed, uppercasing the first letter of a words and keeping uppercase roman numerals and the letters A,B,C after the house number):

function ucAddress($str) {
// first lowercase all and use the default ucwords
    $str = ucwords(strtolower($str));
// let's fix the default ucwords...
// uppercase letters after house number (was lowercased by the strtolower above)
    $str = mb_eregi_replace('\b([0-9]{1,4}[a-z]{1,2})\b', "strtoupper
('\\1')", $str, 'e');
// the same for roman numerals
    $str = mb_eregi_replace('\bM{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})\b', "strtoupper('\\0')", $str, 'e');
    return $str;
}

squeegee ¶

15 years ago

well, if you just calculated the length of the find and replace strings once instead of on every loop, it would likely speed it up a lot.

mpnicholas [@t] gmail (dot) com ¶

16 years ago

Regarding the mb_str_ireplace() function: I benchmarked it against mb_eregi_replace() for single-character substitution, and it was significantly slower. Despite avoiding the ereg call, I think the while loop ends slowing you down too much for this to be practical.

marco at thenetworksolution dot it ¶

8 years ago

To selectively uppercase parts of a string via mb_eregi_replace

    $str = mb_eregi_replace('\b([0-9]{1,4}[a-z]{1,2})\b', "strtoupper
('\\1')", $str, 'e');

Full example, how to fix an address manually typed, uppercasing the first letter of a words and keeping uppercase roman numerals and the letters A,B,C after the house number):

function ucAddress($str) {
// first lowercase all and use the default ucwords
    $str = ucwords(strtolower($str));
// let's fix the default ucwords...
// uppercase letters after house number (was lowercased by the strtolower above)
    $str = mb_eregi_replace('\b([0-9]{1,4}[a-z]{1,2})\b', "strtoupper
('\\1')", $str, 'e');
// the same for roman numerals
    $str = mb_eregi_replace('\bM{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})\b', "strtoupper('\\0')", $str, 'e');
    return $str;
}

Dr. Marco Marsala
Network Solution srl
http://www.realizzazionesitigenova.it

ms2705335 at gmail dot com ¶

5 years ago

As trng mentioned before you can use \\n for replacement but NOT \\\\n as mentioned in preg_replace docs. So string definition will be like:
$str = '\\1';