php PHP电子邮件验证
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PHP email validation
提问by Mark Lalor
For PHPwhat is the best email validation using preg, NOTeregbecause it's deprecated/removed.
对于PHP，使用preg的最佳电子邮件验证是什么，而不是ereg因为它已弃用/删除。
I don'tneed to check if the website exists (it's not like maximum security).
我并不需要检查站点存在（它不是像最大的安全性）。
I've found many ways with eregbut they (obviously) aren't good practice.
我已经找到了很多使用ereg 的方法，但它们（显然）不是很好的做法。
回答by Artefacto
I suggest you use the FILTER_VALIDATE_EMAILfilter:
我建议你使用FILTER_VALIDATE_EMAIL过滤器：
if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
//valid
}
You can also use its regular expressiondirectly:
你也可以直接使用它的正则表达式：
"/^(?!(?:(?:\x22?\x5C[\x00-\x7E]\x22?)|(?:\x22?[^\x5C\x22]\x22?)){255,})(?!(?:(?:\x22?\x5C[\x00-\x7E]\x22?)|(?:\x22?[^\x5C\x22]\x22?)){65,}@)(?:(?:[\x21\x23-\x27\x2A\x2B\x2D\x2F-\x39\x3D\x3F\x5E-\x7E]+)|(?:\x22(?:[\x01-\x08\x0B\x0C\x0E-\x1F\x21\x23-\x5B\x5D-\x7F]|(?:\x5C[\x00-\x7F]))*\x22))(?:\.(?:(?:[\x21\x23-\x27\x2A\x2B\x2D\x2F-\x39\x3D\x3F\x5E-\x7E]+)|(?:\x22(?:[\x01-\x08\x0B\x0C\x0E-\x1F\x21\x23-\x5B\x5D-\x7F]|(?:\x5C[\x00-\x7F]))*\x22)))*@(?:(?:(?!.*[^.]{64,})(?:(?:(?:xn--)?[a-z0-9]+(?:-[a-z0-9]+)*\.){1,126}){1,}(?:(?:[a-z][a-z0-9]*)|(?:(?:xn--)[a-z0-9]+))(?:-[a-z0-9]+)*)|(?:\[(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){7})|(?:(?!(?:.*[a-f0-9][:\]]){7,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?)))|(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){5}:)|(?:(?!(?:.*[a-f0-9]:){5,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3}:)?)))?(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))(?:\.(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))){3}))\]))$/iD"
But in that case, if a bug is found in the regular expression, you'll have to update your program instead of just updating PHP.
但在这种情况下，如果在正则表达式中发现错误，您将不得不更新您的程序，而不仅仅是更新 PHP。
回答by nico
Unless you want to use a very very long regular expressionsyou'll run into valid email addresses that are not covered (think Unicode). Also fake email addresses will pass as valid, so what is the point of validating if you can simply write [email protected] and get away with it?
除非您想使用非常长的正则表达式，否则您 会遇到未涵盖的有效电子邮件地址（想想 Unicode）。虚假的电子邮件地址也将作为有效地址通过，那么验证是否可以简单地编写 [email protected] 并逃脱它的意义何在？
The best way to validate email addresses is to send a confirmation email with a link to click. This will only work if the email address is valid: easy, and no need to use regex.
验证电子邮件地址的最佳方法是发送带有单击链接的确认电子邮件。这仅在电子邮件地址有效时才有效：简单，无需使用正则表达式。
回答by Gaurav Gupta
function check_email($check) {
$expression = "/^[a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\.([a-zA-Z]{2,4})$/";
if (preg_match($expression, $check)) {
return true;
} else {
return false;
}
}
Call it in if() condition as below example :
在 if() 条件下调用它，如下例所示：
if(!check_email($_REQUEST['ContactEmail'])){
$register_error ="Enter the correct email address!<br />";
$reg_error=1;
}
