c - 逐行写？

Question

我有下面的代码。我想逐行写入所有新数据，我该怎么做？我的代码工作正常，但它写入的数据彼此相邻。

////////////////////////////////////
char timedate[13];
char USERID[] ="100050"; 
char *p;
p=fetch_time(); //the function returns a string (char[13])
strcpy(timedate, p);

char log_sensor_event[20];
sprintf(log_sensor_event, "%s %s",timedate, USERID);

FILE *fp2;
fp2=fopen("/home/eagle/Desktop/log_file.txt", "ab");
if(fp2 == NULL){
    perror("log_file.txt open failed");
    exit(EXIT_FAILURE);
}
write(log_sensor_event, sizeof(log_sensor_event[0]), sizeof(log_sensor_event)/sizeof>(log_sensor_event[0]), fp2);
fputc('\n', fp2);
fclose(fp2);

Answer 1

您创建的字符串没有换行符:

sprintf(log_sensor_event, "%s %s",timedate, USERID);

试试这个:

sprintf(log_sensor_event, "%s\n %s",timedate, USERID);