SDFS and File question

[fapplin]

I was looking at the ReadCvsFile example under Examples/ESP8266SdFat.

SDFS.begin() mounts the filesystem (on your attached SD card), but then you can use normal C functions like fopen(), fprintf(), fseek(), fread(), etc.? Am I understanding this correctly?

Frank

[earlephilhower]

No, that's leftover from the faked stuff in the upstream code. SdFat basically rewrote their own versions of the POSIX standard IO stuff, but it's incompatible with cores which support other filesystems. You'll want to use the FS class methods, see the LittleFS example or https://arduino-pico.readthedocs.io/en/latest/fs.html

[earlephilhower]

Why not use LittleFS instead? All calls except the begin() call will be the same. Of course, you'll need to use the FS uplaoder to put in the actual file (or hardcode its writing in setup()). But after auto f = LittleFS.open("a.ini", "r"); all the rest of the code will be identical, LittleFS or SDFS.

[fapplin]

I'm currently using LittleFS and it's working fine, but I have 2 reasons for changing to an SD card. 1) I want users to be able to easily edit a file on an SD card to add some user-defined items. Currently, it's done via a web page which is rather cumbersome for something simple. 2) I wanted the double tap on the reset , so user can download any upgrades, set it in BOOTSEL mode, and just drag the update to the USB storage device. I wasn't sure if the LittleFS file would still be intact.

[earlephilhower]

No worries, I was only suggesting it as a stopgap while waiting for the new HW.

FWIW, LittleFS is preserved between app upgrades, unless you change the flash size.

[fapplin]

Hey Earle. I've made the INI code into a class, but (again) won't be able to test it until my SD board arrives (hopefully Monday or Tuesday). Let me know if you're interested in it after I've put it through some tests.

[earlephilhower]

Great! I suggest you look at making it into a full-fledged Arduino library, if you think it's of general utility. That way anyone can find it (and use it on ESP32 or ESP8266 or the Pico, maybe others). See https://docs.arduino.cc/learn/contributions/arduino-creating-library-guide and https://github.com/arduino/library-registry

[fapplin]

OK. Thanks. I lived in the Windows world for half my career as a programmer/consultant. So, .ini files were how you did almost anything configuration-wise. Now, I don't touch Windows unless I have to. :-) Frank ======================================================================= The price of greatness is responsibility. - Winston Churchill On Friday, October 7, 2022 at 11:58:12 AM EDT, Earle F. Philhower, III ***@***.***> wrote: Great! I suggest you look at making it into a full-fledged Arduino library, if you think it's of general utility. That way anyone can find it (and use it on ESP32 or ESP8266 or the Pico, maybe others). See https://docs.arduino.cc/learn/contributions/arduino-creating-library-guide and https://github.com/arduino/library-registry — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you authored the thread.Message ID: ***@***.***>