问题
i need to check, if the string in my PHP code contains only a specified list of characters. But as some of them might need scape, i just can't get it to work. I have tried everything, but it just doesen't work...
The required validation is:
- 0-9
- A-Z
- a-z
- chars: .%^&()$#@!/-+/
Basicaly, i want to check if there is an unknown ascii character (i don't know if there is a function to do that already).
My code is like this now:
if(preg_match("/[A-Za-z0-9\.\#\-\+\*\\\/\=\_\%\$\(\)]/", $cmd) === false)
So, all of the chars are special?
回答1:
You might be missing a * at the end of the regexp. Also you could instead have the set expressed like [\x00-\x7F] (taken from here).
This should work:
[\x00-\x7F]*
回答2:
No, all of those characters are not special. If you're unsure, you can let PHP do the escaping for you with preg_quote():
$regex = '/[A-Za-z0-9' . preg_quote( '.%^&()$#@!/-+/', '/') . ']+/';
if( !preg_match( $regex, $cmd))
Also, preg_match() returns an int, and you're doing === on a boolean, which will never hold true, since they will never be of the same type. You can simply check for if( !preg_match()).
回答3:
if(preg_match("/[.%^&()$#@!/+-a-zA-Z\d\s]+/", $cmd) === false)
and if you need anchors if(preg_match("/^[.%^&()$#@!/+-a-zA-Z\d\s]+$/", $cmd) === false)
来源：https://stackoverflow.com/questions/11811301/regular-expression-for-allowed-characters