Question

I am trying to validate a file name/ folder name when user try to change the name.
I know I should use Regex/ NSPredicate. However, I didn’t figure out after hours researching.
Appreciate if any experts can help me out.
Thanks a lot.

Was suggested by Madhumal Gunetileke:
I revised his code as below. It works for my case.

NSCharacterSet * set = [NSCharacterSet characterSetWithCharactersInString:@"\\/:*?\"<>|"];
    if ([newName rangeOfCharacterFromSet:set].location != NSNotFound) {
        NSLog(@"illegal Name");
        return;
    }

Answer 1

If you’re simply looking out to check whether the new name users provide are valid or not, you could try something like this;

NSString *yourString = @"<the name you want to verify comes here>";
NSCharacterSet * set = [[NSCharacterSet characterSetWithCharactersInString:@"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ0123456789"] invertedSet];
if ([yourString rangeOfCharacterFromSet:set].location != NSNotFound) {
    NSLog(@"NOT Legal");
}
else {
    NSLog(@"Legal");
}