Update file on FAT SF on the fly

[dkilshtein9]

Posted on December 04, 2012 at 12:50

Sorry for the trivial question but I need to add some data to a text file on the fly.

Each time I need to open an existing file and add a line of text to it then close (to avoid data loss on power off)I'm new to a FS programming and I can't find the option for append (a+). Can I do it on the stm3220g-eval? Do I have to read the entire file content then create a new file to store the data in it? #stm3220g-eval #fs-f_lseek-stm3220g-eval #fat-stm32 #file-system #filesystem #fatfs

[Tesla DeLorean]

Posted on December 04, 2012 at 14:53

Trivial in the sense you could read the documentation, use FA_OPEN_ALWAYS, along with FA_READ/WRITE, and f_lseek to the end of the file

http://elm-chan.org/fsw/ff/en/open.html

[Andrew Neil]

Posted on December 04, 2012 at 14:56

Do you mean FatFs ?

If so, the documentation is here:

http://elm-chan.org/fsw/ff/00index_e.html

 - note also the Resources links...''Each time I need to open an existing file and add a line of text to it then close (to avoid data loss on power off)'' If you are using FatFs, see:

http://elm-chan.org/fsw/ff/en/sync.html

FatFs, Filesystem, File System

[dkilshtein9]

Posted on December 04, 2012 at 19:47

Thanks a lot,

I fund the f_lseek but it didn't work(it kept crashing) . Then I found the bug in a whole different location.

Now it works perfectly!!!