pattern

[Javeed SAR]

        Hi all,
        I want to input a string which is used to create file name, and I
want to 
        allow input string to consist of letters(SDK) at the start and only
IR and DEV inbetween, and numbers(0-9) and 
        underscore( _ ) within file name. 
        Is the pattern right. 
        m/^SDK[0-9]|^SDK_[0-9]|^SDK_[0-9]_IR|^SDK_[0-9]_IR_DEV$/ 


        if ($input =~ /what pattern /){ 
        create file 
        } else { 
        exit 0; } 

Regards