Validate an input for special characters

[vimrda]

Hello,

I am developing a simple form to collect user information. I want a sample PHP code, that will validate the input string to display whether it has any of the below list of special character in the string.

Special Characters ( - & ' " / \ % * # )

Can one of please help me. More detailed info below:

I have a form that submits the input to a PHP modules using Ajax Post. When my PHP modules reads the POST values, it should validate to check if the special characters are available, if it is available then display "No special characters allowed"

Anyones help will be so greatful

Thank you.
Vim

[johanafm]

So you are going to check for presence of characters that are NOT allowed rather than checking for absence of anything BUT those that actually are allowed?

Which would mean that you allow ₳ ฿ ₵ ¢ ₡ ₢ ₠ $ ₫ ৳ ₯ € ƒ ₣ ₲ ₴ ₭ ℳ ₥ ₦ ₧ ₱ ₰ £ ₹ ₨ ₪ ₸ ₮ ₩ ¥ ៛ among other things?

Conclusion, never use black lists - always use white lists. If you allow only 'a', you do not perform 27 checks to see that no other alphabetical character is present (apart from the check to see that it's only alphabetical characters).

Next up, I wonder why you are going to disallow those characters specifically?

And to answer your question in case I'm overly suspicious of your motives and solution, see [man]strpos[/man] and [man]preg_match[/man]