fatfs/documents/res/app1.c

   1 /*------------------------------------------------------------/
   2 / Open or create a file in append mode
   3 / (This function was sperseded by FA_OPEN_APPEND flag at FatFs R0.12a)
   4 /------------------------------------------------------------*/
   5
   6 FRESULT open_append (
   7     FIL* fp,            /* [OUT] File object to create */
   8     const char* path    /* [IN]  File name to be opened */
   9 )
  10 {
  11     FRESULT fr;
  12
  13     /* Opens an existing file. If not exist, creates a new file. */
  14     fr = f_open(fp, path, FA_WRITE | FA_OPEN_ALWAYS);
  15     if (fr == FR_OK) {
  16         /* Seek to end of the file to append data */
  17         fr = f_lseek(fp, f_size(fp));
  18         if (fr != FR_OK)
  19             f_close(fp);
  20     }
  21     return fr;
  22 }
  23
  24
  25 int main (void)
  26 {
  27     FRESULT fr;
  28     FATFS fs;
  29     FIL fil;
  30
  31     /* Open or create a log file and ready to append */
  32     f_mount(&fs, "", 0);
  33     fr = open_append(&fil, "logfile.txt");
  34     if (fr != FR_OK) return 1;
  35
  36     /* Append a line */
  37     f_printf(&fil, "%02u/%02u/%u, %2u:%02u\n", Mday, Mon, Year, Hour, Min);
  38
  39     /* Close the file */
  40     f_close(&fil);
  41
  42     return 0;
  43 }
  44