FatFS文件末尾附加数据的方法

eric2013

http://elm-chan.org/fsw/ff/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. }

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