【程序练习】——每隔1秒向文件中写入一行记录

编程读写一个文件test.txt，每隔1秒向文件中写入一行记录，类似于这样：

1 2009-7-30 15:16:42
2 2009-7-30 15:16:43

该程序应该无限循环，直到按Ctrl-C终止。下次再启动程序时在test.txt文件末尾追加记录，并且序号能够接续上次的序号，比如：

1 2009-7-30 15:16:42
2 2009-7-30 15:16:43
3 2009-7-30 15:19:02
4 2009-7-30 15:19:03
5 2009-7-30 15:19:04

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

void writefile()
{
    FILE *fp;
    time_t timep;
    struct tm *p;
    int n = 10;    

    while(1){

        if((fp = fopen("text.txt","aw")) == NULL){
            perror("open file text.txt");
            exit(1);
        }    
        time(&timep);
        p = localtime(&timep);

        if(fprintf(fp,"%d-%d-%d %d:%d:%d
",p->tm_year + 1900,p->tm_mon,p->tm_mday,p->tm_hour,p->tm_min,p->tm_sec) < 0){
            printf("error!
");
        }    
    
        fprintf(stdout,"%d-%d-%d %d:%d:%d
",p->tm_year + 1900,p->tm_mon,p->tm_mday,p->tm_hour,p->tm_min,p->tm_sec);    
        fclose(fp);
        sleep(1);
    }

}

int main(int argc, char *argv[])
{
    writefile();
    return 0;
}