I have a filter at the beginning of my CGI: 
my $sid = $q->param ('sid');

if($sid !~ /0-9/) { 
    print "Content-type: text/html\n\n";
    print "Invalid Input!"; 
    exit(0); 
}

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I want it to exit out if the input contains anything but numbers. My input should be any number from 0 to 99999.

This code seems to match every input. What's wrong?

In reply to Filtering CGI Input by awohld

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