linux产生随机数

        unsigned char ws222_ran_data[8]={0};

        struct timeval tpstart;
        gettimeofday(&tpstart,NULL);
        srand(tpstart.tv_usec);
ws222_ran_data[0]=1+(int) (100.0*rand()/(255+1.0));
ws222_ran_data[1]=1+(int) (100.0*rand()/(255+1.0));
ws222_ran_data[2]=1+(int) (100.0*rand()/(255+1.0));
ws222_ran_data[3]=1+(int) (100.0*rand()/(255+1.0));
ws222_ran_data[4]=1+(int) (100.0*rand()/(255+1.0));
ws222_ran_data[5]=1+(int) (100.0*rand()/(255+1.0));
ws222_ran_data[6]=1+(int) (100.0*rand()/(255+1.0));
ws222_ran_data[7]=1+(int) (100.0*rand()/(255+1.0));