How do I read/write files in my phone using C?

Question

The code I wrote shows timeout and segmentation faults.
https://code.sololearn.com/c2PzHwwRg6xR/?ref=app

Answer 1

Non web codes on Code Playground are sent to SL's server, where they are compiled, executed and have their output sent back to the client (us). As such, it is not possible to access files local to our mobile devices via codes in Code Playground.

Answer 2

That is not possible in SoloLearn. There are probably apps on the app store/play store that can do this.