regexp to partly hide email? [closed]

Answer 1

A replacement callback is an option.

echo preg_replace_callback('/(?<=^.).+(?=@)/u', function($match) {
    return str_pad('', strlen($match[0]), '*');
}, "something@something.com");
//s*******@something.com

Note I use an anonymous function as the callback - this is PHP >= 5.3 only. If you're on < 5.3, use a named function or one created with function_create().

Answer 2

Why use regexp at all when this can be done much faster?

if(($pos = mb_strpos($email,'@')) > 0) {
    for($i=1;$i<=$pos;$i++) {
        $email[$i] = '*';
    }
}

Answer 3

You could use the preg_replace_callback() function from the PCRE family. You can use the u modifier to support UTF-8.

Please note there are some smaller differences between the PCRE (preg_) and POSIX (ereg_) way, besides that the latter is deprecated.

Answer 4

There is no need to use a callback function, a single regular expression can do it.

(?<=.).(?=.*@)

• (?<=.), make sure there is at least one character before so it won't replace the first character.
• ., match any character.
• (?=.*@), make sure there is a @ somewhere after the character.

Example with function changed to preg_replace with unicode modifier (as suggested):

echo preg_replace('/(?<=.).(?=.*@)/u','*','漢aelena@tratata.com');

Outputs:

漢******@tratata.com

Answer 5

<?php

$email = '漢aelena@tratata.com';

    $email = preg_replace_callback('#^(.){1}(.*?)@#u', function($matches)
            {
                return $matches[1] . str_repeat('*', mb_strlen($matches[2])) . '@';
            },
    $email);

echo $email; # 漢******@tratata.com