毫秒级数据fprintf打印输出

#include <sys/time.h>
#include <time.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
    struct timeval time_ticks;
    unsigned int pre_value,prev_s_value;;
    unsigned int cur_value;
    unsigned int interval_tick;
    gettimeofday(&time_ticks,NULL);
    pre_value = cur_value = time_ticks.tv_usec;
    prev_s_value = time_ticks.tv_sec;
    for(;;)
    {
        gettimeofday(&time_ticks,NULL);
        cur_value = time_ticks.tv_usec;
        //if(cur_value != pre_value)
        {
            /*
            if(cur_value > pre_value)
            {
                interval_tick = cur_value - pre_value;
            }else interval_tick = pre_value - cur_value;//从0xfffffxxx时刻开始进入的程序
            */
            interval_tick = cur_value - pre_value;
            if(interval_tick >= 1000)
            {
                pre_value = cur_value;
                fprintf(stderr,"C");
            }
        }
        cur_value = time_ticks.tv_sec;
        if(cur_value - prev_s_value)
        {
            prev_s_value = cur_value;
            fprintf(stderr,"S");
        }
    }
}