preg_match: All characters must match

Question

I have an user input which gets checked if the chars are on the whitelist.

My regular expression:

[A-Za-z0-9_~\-!@#\s\$%\^&\*\(\)\=\:\;\+\°\´\[\]\{\}\§\"\'\ß\ä\ö\ü\%\.\,\>\<\|\€]+$

My code part:

$check = preg_match($pattern, trim($input));

Now, when the $input variable has for example the value abc²³ , the input gets blocked. But when it has the value abc²³def , the content won't get blocked.

How can I check every character of a string?

Answer 1

You simply forgot the start of string anchor: ^

^[\p{L}\d_~\-!@#\s$%^&*()=:;+°´\[\]{}§"'%.,><|€]+$

I also simplified the regex. Note that I replaced A-Za-Zßäöü with \\p{L} which will accept letters from any language.

Answer 2

You have to anchor the regex at the begining:

^[A-Za-z0-9_~\-!@#\s\$%\^&\*\(\)\=\:\;\+\°\´\[\]\{\}\§\"\'\ß\ä\ö\ü\%\.\,\>\<\|\€]+$

You also may simplify a bit:

^[\w~\-!@#\s$%\^&*()=:;+°´\[\]{}§"'ßäöü%.,><|€]+$

Or, even, using unicode properties:

^[-\p{L}\p{N}_~!@#\s$%\^&*()=:;+°´\[\]{}§"'%.,><|€]+$