Warning: preg_match() [function.preg-match]: Unknown modifier '_'

Question

Following is the regex I am trying to use

$eregicheck = "^([-!#\$%&'*+./0-9=?A-Z^_`a-z{|}~])+@([-!#\$%&'*+/0-9=?A-Z^_`a-z{|}~]+\\.)+[a-zA-Z]{2,4}\$";

I changed the following lines

return eregi($eregicheck, $emailtocheck);

to

return preg_match($eregicheck, $emailtocheck);

But I dont know why I am getting the error

Warning: preg_match() [function.preg-match]: Unknown modifier '_'

score 1 · Answer 1 · answered Nov 30 '13 at 21:26

1

Try:

^([-!#\$%&'*+./0-9=?A-Z\^_`a-z{|}~])+@([-!#\$%&'*+/0-9=?A-Z\^_`a-z{|}~]+\\.)+[a-zA-Z]{2,4}\$

You need to escape ^. It is a special character, which provides instructions to RE.

answered Nov 30 '13 at 21:26

Kohjah Breese

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You missed one delimiter '^' at the end. Anyways. It worked. Thanks – Venkateshwaran Selvaraj Nov 30 '13 at 21:32

score 1 · Accepted Answer · answered Nov 30 '13 at 21:30

1

You're getting this error because php requires delimiters before and after the regex pattern, which in your case it assumes to be ^ and after the delimiters follow the modifiers, in your case _. Since there's no such modifier hence the error. Change the code to:

$eregicheck = "/^([-!#\$%&'*+.\/0-9=?A-Z^_`a-z{|}~])+@([-!#\$%&'*+\/0-9=?A-Z^_`a-z{|}~]+\\.)+[a-zA-Z]{2,4}\$/";

P.S.: That seems like quite a complex regex, are you sure it can't be simplified? :P

answered Nov 30 '13 at 21:30

php_nub_qq

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It worked too flawlessly and I did not try simplifying since it is working properly. Suggest if you can do so. – Venkateshwaran Selvaraj Nov 30 '13 at 21:45
@Venky is this regex for validating email addresses? – php_nub_qq Nov 30 '13 at 21:48
Yes. To verify valid email ids – Venkateshwaran Selvaraj Nov 30 '13 at 22:23
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@Venky well you don't actually need it at all, as `filter_var()` is now around. http://php.net/manual/en/function.filter-var.php – php_nub_qq Nov 30 '13 at 22:30
thanks. I never knew it. – Venkateshwaran Selvaraj Nov 30 '13 at 22:49

Warning: preg_match() [function.preg-match]: Unknown modifier '_'

2 Answers2