You may use the following regular expression:
/^[a-zA-Z0-9_-+ t/@%.]+$/
For example:
return (preg_match('/^[a-zA-Z0-9_-+ t/@%.]+$/', $str);
You may use the following regular expression:
/^[a-zA-Z0-9_-+ t/@%.]+$/
For example:
return (preg_match('/^[a-zA-Z0-9_-+ t/@%.]+$/', $str);