fatfs/doc/img/app1.c

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