所有时间测试函数

/*
 * timeTest.c
 *
 *  Created on: Aug 28, 2013
 *      Author: zsf
 */


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>

int main(int argc,char *argv[]){
#if 0
//获取时间
{
    //取得Ｓ级的时间
        time_t time_s=0;
        struct tm *nowtm=NULL;
        char buf[64]={0};
        char tmbuf[64] = {0};
        if(-1==time (&time_s)){
            perror("time error"); //获取当前时间
        }
        printf ("time is [%d]
", (int)time_s);
        printf ( "The current local time: %s", ctime(&time_s));
        if(NULL==ctime_r(&time_s,tmbuf)){
            perror("asctime error!");
        }
        printf ( "The current local time: %s",tmbuf);
        printf("----------------------------------------------------------------------
");

        //０时区时间
        struct tm lasttm;
        bzero(&lasttm,sizeof(struct tm));
        nowtm=gmtime(&time_s);
        //用户自定义格式输出时间
        strftime(buf,sizeof(buf),"%Y-%m-%d %H:%M:%S",nowtm);
        printf ( "The current local time: %s(s)
",buf);

        if(NULL==gmtime_r(&time_s,&lasttm)){
            perror("asctime error!");
        }
        printf ( "The current local time: %s",asctime(&lasttm));

        bzero(&lasttm,sizeof(struct tm));
        strptime(buf,"%Y-%m-%d %H:%M:%S",&lasttm);
        printf ( "The current local time: %s", asctime(&lasttm));
        printf("----------------------------------------------------------------------
");

        //当前时区时间,内核时区未设置时亦取０时区时间
        nowtm=NULL;
        nowtm=localtime(&time_s);
        //用户自定义格式输出时间
        strftime(buf,sizeof(buf),"%Y-%m-%d %H:%M:%S",nowtm);
        printf ( "The current local time: %s(s)
",buf);

        bzero(&lasttm,sizeof(struct tm));
        strptime(buf,"%Y-%m-%d %H:%M:%S",&lasttm);
        printf ( "The current local time: %s", asctime(&lasttm));
        printf("----------------------------------------------------------------------
");




    //取得us级的时间
        time_t time_ms=0;
        struct timeval tv;
        memset(&tmbuf,sizeof(tmbuf),0);
        memset(&buf,sizeof(buf),0);
        bzero(&tv,0);
        if(gettimeofday(&tv,NULL)){
            perror("gettimeofday error!");
        }
        printf ("time 秒 is [%d]
", (int)tv.tv_sec);
        printf ("time 微秒　is [%d]
", (int)tv.tv_usec);
#if 0
        long int ts;
        ts = tv.tv_sec*1000000+ tv.tv_usec;
        ts /=1000000;
        printf ( "The current local time: %s",ctime(&ts));
#endif
        printf ( "The current local time: %s",ctime(&tv.tv_sec));
        nowtm = localtime(&tv.tv_sec);
        strftime(tmbuf, sizeof(tmbuf), "%Y-%m-%d %H:%M:%S", nowtm);
        //将毫秒值追加到 strftime 转换的字符串末尾
        snprintf(buf, sizeof(buf), "%s.%06d", tmbuf, (int)tv.tv_usec);
        printf("The current local time is %s(s)
",tmbuf);
        printf("The current local time is %s(us)
",buf);

    //取得纳秒级的时间
        struct timespec tp;
        bzero(&tp,sizeof(tp));
        //系统实时时间,随系统实时时间改变而改变,即从UTC1970-1-1 0:0:0开始计时,中间时刻如果系统时间被用户该成其他改变,则对应的时间相应改变
        if(clock_gettime(CLOCK_REALTIME, &tp)){
            perror("clock_gettime error!");
        }
        nowtm = NULL;
        nowtm = localtime(&tp.tv_sec);
        memset(&tmbuf,sizeof(tmbuf),0);
        memset(&buf,sizeof(buf),0);
        strftime(tmbuf, sizeof(tmbuf), "%Y-%m-%d %H:%M:%S", nowtm);
        snprintf(buf, sizeof(buf), "%s.%06d", tmbuf, (int)tp.tv_nsec);
        printf("The current local time is %s(s)
",tmbuf);
        printf("The current local time is %s(ns)
",buf);

        //CLOCK_MONOTONIC:从系统启动这一刻起开始计时,不受系统时间被用户改变的影响
        bzero(&tp,sizeof(tp));
        if(clock_gettime(CLOCK_MONOTONIC, &tp)){
            perror("clock_gettime error!");
        }
        nowtm = NULL;
        nowtm = localtime(&tp.tv_sec);
        memset(&tmbuf,sizeof(tmbuf),0);
        memset(&buf,sizeof(buf),0);
        strftime(tmbuf, sizeof(tmbuf), "%Y-%m-%d %H:%M:%S", nowtm);
        snprintf(buf, sizeof(buf), "%s.%06d", tmbuf,(int) tp.tv_nsec);
        printf("The current local time is %s(s)
",tmbuf);
        printf("The current local time is %s(ns)
",buf);
}
#endif

#if 0
CLOCK_REALTIME - can jump - can slew - if ntp is running this clock is always kept close to GMT. even if hardware is not 100% correct, ntp will correct everything over time.

CLOCK_MONOTONIC - cannot jump - can slew !!! (because of ntp) - it is not kept in sync with GMT. but the "speed" of seconds is kept in sync with GMT by varying it constantly by ntp.

CLOCK_MONOTONIC_RAW - cannot jump - cannot slew ! - the speed of seconds is not the same as the speed of GMT seconds since the hardware timer is never 100% exact and ntp daemon does NOT have influence here
#endif
#if 1
{
#if 0
        if(argc<7){
            printf("USage Year,Month,Day,Hour,Minute,Second
");
            printf("Example: ./test 2013 8 23 12 30 30
");
            printf("this example time is 2013-8-23 12:30:30
");
        }
        struct tm nowtm;
        time_t   tp;
        bzero(&nowtm,sizeof(struct tm));
        nowtm.tm_year = atoi(argv[1]);
        nowtm.tm_mon  = atoi(argv[2]);
        nowtm.tm_mday = atoi(argv[3]);
        nowtm.tm_hour = atoi(argv[4]);
        nowtm.tm_min  = atoi(argv[5]);
        nowtm.tm_sec  = atoi(argv[6]);

#endif
        struct tm nowtm;
        time_t   tp;
#if 1
        //获取当前时间到struct tm中
        bzero(&nowtm,sizeof(struct tm));
        if(-1==time(&tp)){
            perror("time error!");
        }
        if(NULL==localtime_r(&tp,&nowtm)){
            perror("localtime error!");
        }
        printf ( "The current local time: %s", asctime(&nowtm));
#endif
#if 0
        //用户指定时间设置
        char tmbuf[64] = {"2013-5-22 13:47:50"};
        bzero(&nowtm,sizeof(struct tm));
        if(NULL==strptime(tmbuf,"%Y-%m-%d %H:%M:%S",&nowtm)){
            perror("strftime error!
");
        }
        printf("day is %d
",nowtm.tm_mday);
#endif
#if 1
        tp = mktime(&nowtm);
        if(-1==tp){
            perror("mktime error!");
        }
        //取得系统设置时间的权限比如sudo 或是切换到root用户
        if(-1==stime(&tp)){
            perror("stime error!");
        }
        if(-1==time(&tp)){
            perror("time error!");
        }
        printf ( "The current local time: %s", ctime(&tp));
#endif
#if 1

        struct timeval tv;
        bzero(&tv,sizeof(struct timeval));
        tv.tv_sec=tp;
        //取得系统设置时间的权限比如sudo 或是切换到root用户
        if((-1==settimeofday(&tv,NULL))){
            perror("settimeofday error!
");
        }
        if(-1==time(&tp)){
            perror("time error!");
        }
        printf ( "The current local time: %s", ctime(&tp));
#endif
#if 0
        //以硬件时间为准，设置系统时间
        system("hwclock -s");
        //以系统时间为准，设置硬件时间
        system("hwclock -w");
        //显示硬件时间
        system("hwclock --show");
        return 0;
#endif
}
#endif

}

CC = gcc 
AR = 
LD =

TARGET = time
OBJECT :=$(patsubst %.c,%.o,$(wildcard ./*.c))

LIB    = -lrt

all:$(TARGET)
        @echo "Build OK!"
$(TARGET):$(OBJECT)
    $(CC) $^ -o $@ $(LIB)
%.o:%.c
    $(CC) -g $<  -c  -o $@
    
.PHONY:clean
clean:
    rm -rf $(TARGET)
    rm -rf $(OBJECT)
    @echo "Clean up!"