带有空格的PHP电子邮件提取器

Question

我有一个从字符串中提取电子邮件的功能

$extractor = function ($str) {
$str = str_replace('[at]', '@', $str);
$str = str_replace('(dot)', '.', $str);
$regexp = '/([a-z0-9_.-])+@(([a-z0-9-])+.)+([a-z0-9]{2,4})+/i';
preg_match_all($regexp, $str, $m);
return isset($m[0]) ? $m[0] : [];
};
$test_string = 'This is a test string...
[e-mail]
Test different formats:
[e-mail];
<a href="[e-mail]">foobar</a>
<[e-mail]>
strange formats:
[e-mail]
test6[at]example.org
[e-mail]
test8@ example.org
test9@!foo!.org
test10.abc [at] hello (dot) com
foobar
';
dd($extractor($test_string));

由于@和[at]之前/之后的空格，无法提取这些电子邮件。

test8@ example.org
test10.abc [at] hello (dot) com

我怎么能忽略正则表达式中的那些空格呢。非常感谢。

Answer 1

我建议通过删除[at]、(dot)和@周围的任何空白来对输入进行更多的预处理，即替换

$str = str_replace('[at]', '@', $str);
$str = str_replace('(dot)', '.', $str);

带有

$str = preg_replace('/s*(?:[at]|@)s*/', '@', $str); // replace [at] or @ with any amount of spaces before and after with @
$str = preg_replace('/s*(dot)s*/', '.', $str); // replace (dot) with any amount of spaces before and after with .

请参阅PHP演示：

$extractor = function ($str) {
$str = preg_replace('/s*(?:[at]|@)s*/', '@', $str);
$str = preg_replace('/s*(dot)s*/', '.', $str);
$regexp = '/b[a-z0-9_.-]+@(?:[a-z0-9-]+.)+[a-z0-9]{2,4}b/i';
preg_match_all($regexp, $str, $m);
return isset($m[0]) ? $m[0] : [];
};

输出：

Array
(
[0] => [e-mail]
[1] => [e-mail]
[2] => [e-mail]
[3] => [e-mail]
[4] => [e-mail]
[5] => [e-mail]
[6] => [e-mail]
[7] => [e-mail]
[8] => [e-mail]
)