Use this regex:
if(preg_match('/[[:punct:]]/', $_POST['username']) !== 0) {
// string contains other characters, write the code
}
The POSIX class [:punct:] means matches any punctuation and symbols in your
string and that includes [!"#$%&'()*+,\-./:;<=>?@[\\\]^_`{|}~]
Regards,
Igor Escobar
*Software Engineer
*
+ http://blog.igorescobar.com
+ http://www.igorescobar.com
+ @igorescobar <http://www.twitter.com/igorescobar>
On Thu, Sep 22, 2011 at 9:17 AM, Nilesh Govindarajan
<contact@xxxxxxxxxxxx>wrote:
> On Thu 22 Sep 2011 08:25:29 PM IST, Eric wrote:
> > I have this problem when using php because my computer recognizes
> > the characters "." and ".." as an existing file when I use file_exists.
> Also
> > I want to check $_POST["username"] for characters other then A-Z a-z and
> 0-9.
> > If it contains anything other then, I would like to prompt the user but
> > I can't seam to use foreach properly and I don't know how to itterate
> > through the post variable with a for loop while loop or do while loop.
>
> file_exists() for . and .. would always return true, because they
> really exist! . is an alias for the current directory and .. for the
> parent directory. This is irrespective of OS.
>
> To search $_POST["username"] for characters other than A-Z, a-z, 0-9,
> you can use preg_match something like this (there's an alpha class as
> well, but I'm not sure about it):
>
> if(preg_match('(.*)^[A-Za-z0-9]+', $_POST['username']) !== 0) {
> // string contains other characters, write the code
> }
>
> --
> Nilesh Govindarajan
> http://nileshgr.com
>
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