Validate that a string only contains whitelisted characters

Question

I am trying to put a regex match in PHP to find whether the string contains any other invalid characters other than the following characters,

~!@#$%^&*()_-+=\}]{[::'"/>.<,
alpha, space, numeric

I want to print the string if it contains any other character other than the previously mentioned characters

ßab? - Invalid
Ba,-  - Valid

I tried using preg_match() with few inputs but unable to complete it.

Answer 1

Update

This expression will match the negative set of your valid range:

$valid = preg_quote('~!@#$%^&*()_-+=\}]{[::\'"/>.<,', '/');

if (preg_match("/[^$valid\d\sA-Za-z]/", $invalid)) {
        echo "invalid chars\n";
}

I'm using preg_quote() here to make sure all characters are properly escaped.

Old answer

I calculated the negative set based on your question:

if (preg_match('/[\x00-\x08\x0c\x0e-\x1f\x3b\x3f\x60\x7c\x7f-\xff]/', $str)) {
        echo "matches invalid chars\n";
}

To arrive at this set, you can use this code:

$s = '~!@#$%^&*()_-+=\}]{[::\'"/>.<,'
        . join('', range('a', 'z'))
        . join('', range('A', 'Z'))
        . join('', range('0', '9'))
        . " \t\r\v\n";

$missing = count_chars($s, 2);
print_r($missing);

It prints an array of ordinal character codes that's not inside $s; with that you can generate above pattern.