Limiting a string to certain characters

[tibberous]

I am trying to strip out everything from a string except letters, numbers, periods and forward slashes. I figure this will help prevent me a little bit from attacks.

 

Now, this works: $uri = preg_replace("/[^A-Za-z0-9\-\.\/]/", '', $uri);

 

But it that going to be really bad performance wise?

[dsaba]

performance is measured in comparison to something...

to what you would like to compare this too? I don't know..

Run some performance tests in a loop with str_replace.. or whatever it is you'd like to compare it too and find out.

 

Generally speaking though, it depends on the amount of data you are running the regex through, even still, preg is fast.

 

BTW: Your regex will also strip the spaces from a string.

Try:

/[^A-Za-z0-9\-\.\/ ]/

<a href="http://nancywalshee03.freehostia.com/regextester/regex_tester.php?seeSaved=ukbjrqpe">Tested here.</a>