PHP正则验证Email的方法

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

<?php

function validateEmail($email)

{

$isValid = true;

$atIndex = strrpos($email, "@");

if (is_bool($atIndex) && !$atIndex)

{

$isValid = false;

}

else

{

$domain = substr($email, $atIndex+1);

$local = substr($email, 0, $atIndex);

$localLen = strlen($local);

$domainLen = strlen($domain);

if ($localLen < 1 || $localLen > 64)

{

// local part length exceeded

$isValid = false;

}

else if ($domainLen < 1 || $domainLen > 255)

{

// domain part length exceeded

$isValid = false;

}

else if ($local[0] == '.' || $local[$localLen-1] == '.')

{

// local part starts or ends with '.'

$isValid = false;

}

else if (preg_match('/\\.\\./', $local))

{

// local part has two consecutive dots

$isValid = false;

}

else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain))

{

// character not valid in domain part

$isValid = false;

}

else if (preg_match('/\\.\\./', $domain))

{

// domain part has two consecutive dots

$isValid = false;

}

else if(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/', str_replace("\\\\","",$local)))

{

// character not valid in local part unless

// local part is quoted

if (!preg_match('/^"(\\\\"|[^"])+"$/', str_replace("\\\\","",$local)))

{

$isValid = false;

}

}

if ($isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain,"A")))

{

// domain not found in DNS

$isValid = false;

}

}

return $isValid;

}

?>