If there is a DNS problem *and* the default $dns_check value of true is used, valid will fail.
If it is an international domain name, you have to have the php-intl package installed. "(comment)[email protected]"is an invalid E-Mail address per RFC5322 (Appendix A.6.3):"Also, the comments and white space throughout addresses, dates, and message identifiers are all part of the obsolete syntax." FILTER_VALIDATE_URL does not support internationalized domain name (IDN).
The important characteristics of a form handler is that it verifies that the required variables have been set, and that they have appropriate values.
Remember to be thorough as this is your last (only real) line of defence against malicious scripts. Naming the button is useful in case there are multiple forms on the page. In reality we have special functions for validating email addresses and other data types - as will most Java Script libraries.
gmail, yahoo, hotmail, aol have special rules For example : I managed to get this to work with PHP 5.1.6 on Cent OS 5 with minor difficulty.1) Download the PECL filter package2) Extract the tarball3) phpize the directory4) ./configure5) make6) filter-0.11.0/logical_filters.c:: error: ext/pcre/php_pcre.h: No such file or directory7) find / -name php_pcre.h8) Make sure php-devel is installed9) Edit filter-0.11.0/logical_filters.c and replace "ext/pcre/php_pcre.h" with the absolute path of php_pcre.h10) make11) make install12) add "extension=filter.so" to php.ini13) Restart Apache/******************************************* * * These are the function * * check_username is called by check_email * - it compensates for bugs in the php * filter_var function.
* - returns boolean * * check_email is the function to use.
In the previous example we made a faux pas in polluting the global variable space.
You'll notice that we've used PHP to insert the form as the current page.
That's because we are using the "redirect-after-POST" technique as illustrated here: This is explained in more detail in our CAPTCHA article.
* First argument is string, address to * check * Second argument is optional boolean, * whether or not to use DNS to validate * the domain name.
Defaults to true * Returns boolean * */ It evaluates the address in two parts, first evaluating the host and if that legal it then evaluates the user name.