close() problem

"snoppy1314" <snoppy1314@xxxxxxx> · Thu, 16 Apr 2009 20:49:54 +0800



            Hi:
             
            I have three progree: HIT, 
            new-sim300 and pppd, also have a driver cdc-acm.ko(it generates a 
            device file /dev/ttyACM0).
            I call open(/dev/ttyACM0) 
            in HIT, and then call system("./pppd") and 
            system("./new-sim300") in HIT. I think, when  I kill 
            HIT, the close(dev/ttyACM0) will be called automatically.But in 
            fact, the close(dev/ttyACM0) isn't called until the pppd, new-sim300 
            and HIT are all killed.who can tell me why?
            Thanks in advance!
             
             
            　　　　　　　　致
礼！
            2009-04-16
            

            snoppy1314