What characters are allowed in a iOS file name?

Question

I\'m looking for a way to make sure a string can be used as a file name under iOS. I\'m currently in the section of the code that deletes incompatible characters. I\'m wonde

Answer 1

I've had to save remote files locally with filenames containing other characters than basic alpha-numeric characters. I use the method below to strip out potential invalid characters, ensuring it's a valid filename for the filesystem when generating a NSURL using URLWithString:

    filename = [[filename componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] componentsJoinedByString:@"" ];
    filename = [[filename componentsSeparatedByCharactersInSet:[NSCharacterSet illegalCharacterSet]] componentsJoinedByString:@"" ];
    filename = [[filename componentsSeparatedByCharactersInSet:[NSCharacterSet symbolCharacterSet]] componentsJoinedByString:@"" ];
    fileURLString = [NSTemporaryDirectory() stringByAppendingPathComponent:filename];
    fileURL = [NSURL URLWithString:fileURLString];

You may also want to test for collision errors first using:

    [[NSFileManager defaultManager] fileExistsAtPath:[fileURL absoluteString]]