Dear Laurent_R first of all thank you very much for your answer I really don't need to convert the c code into perl all what I need is a perl code do the process as fast as this code do " the part of fuzzy match comparison " just this part which I really . and If there is no module in perl or code could do the same , I only need any one to highlight the library or the module in c that this man used which I can use too as an external c code in my tool. I know that you are monks are very very busy and I only seek for your wisdom to tell me the correct path through this .