[sudhakararaog]

hi

i need to validate a field in a form where a user enters their lodgement number as part of a registration form. this lodgement number can have letters, numbers, spaces and special characters. i do not know exactly what those special characters are, so do i have to define the type of special characters and validate accordingly.

presently my php code for validating the lodgement number is

$lodgementtf = $_POST["lodgementtf"];

if($lodgementtf == "" || !preg_match("/^[a-zA-Z0-9_ <]+$/", $lodgementtf) )
{
echo "display error message":
}


i also have another way of validating

if($lodgementnumber == "" || !preg_match("/^[a-zA-Z0-9_ !-@£$%^&*()]+$/", $lodgementnumber) )

does this mean that the special characters can only be = a space AND _!-@£$%^&*() and no other special characters.

please advice.

thanks.

[TroyTime]

it doesn't make much sense to string validate a field that can have numbers letters spaces AND special characters

but then again, it doesn't make much sense for any "number" to have letters numbers spaces and special characters...

[awatson]

Well, it could make sense in some situations - i.e. like an apartment number (4F or something). But if the range of characters is too wide, it probably does make more sense to check for other things, such as number of characters.

[Mudley]

yeah it doesn't make much sense to validate such a fubared string.

if you need to verify that its valid, trap it for harmfull data (xss, sql, javascript, etc) and compare it with your database

regular expressions are great, but they're slow
don't use them here unless you're matching a specific pattern (like 4 numbers followed by 1 or 2 letters followed by another three numbers followed by a ! or a @ or a $ and then followed by another 2 numbers)