Allow alphanumeric, punctuation, and spaces

Posted by bccarlso on Stack Overflow See other posts from Stack Overflow or by bccarlso
Published on 2010-05-28T16:43:47Z Indexed on 2010/05/28 16:52 UTC
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regex

I'm pretty new to regular expressions, and MAN do they give me a headache. They are so intimidating! For an email campaign I'm doing, a user will click a link out of the email with a few URL parameters filled in for them, to make filling out a form easier. I want to prevent any injection hacks or whatever it's called, but need to allow the $_GET parameters to be alphanumeric, have punctuation, and have spaces. If someone has a good method for this, I'd appreciate it, but right now I have:

foreach($_GET as $m=>$n) {
    $get[$m] = preg_replace('(^[a-z0-9 \-\_\.]+)i',' ',$n);
}

I would like to be able to replace all characters NOT found with this regular expression, which I believe I use ?!, but I can't get that to work either. Any help in getting this to work would be appreciated!

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