Linux C 获得格式化系统时间

（1）Linux C获得格式化系统时间

#include <time.h>  
#include <stdio.h> 
#include <string.h>
int main(void)
{	
	 //printf("%s",s);
    time_t now;
    struct tm *tm_now;
    time(&now);
    tm_now = localtime(&now); 
    printf("now datetime: %d-%d-%d %d:%d:%d\n", 1900+tm_now->tm_year, 1+tm_now->tm_mon, tm_now->tm_mday, tm_now->tm_hour, tm_now->tm_min, tm_now->tm_sec);
    char *message = "nihao";	
    char a1[10],a2[10];
    int n;
    n=10;
    sprintf(a2,"%ld",(1900+tm_now->tm_year)*10000000000+(1+tm_now->tm_mon)*100000000+tm_now->tm_mday*1000000+tm_now->tm_hour*10000+tm_now->tm_min*100+tm_now->tm_sec   );//这样把n写入字符串a2
    printf( "result is \"%s\"\n", a2 );  
    printf("now datetime: %d-%d-%d %d:%d:%d\n", 1900+tm_now->tm_year, 1+tm_now->tm_mon, tm_now->tm_mday, tm_now->tm_hour, tm_now->tm_min, tm_now->tm_sec);

}

（2）Linux C 将数字转化为字符串

sprintf函数

char a1[10],a2[10];
int n;
n=10;
sprintf(a2,"%d",n);//这样把n写入字符串a2