Avoiding Android Symbolic Link loop

问题

Is it possible in Android to have a SymLink (Symbolic Link) that leads to a point higher in the directory tree than the initial directory, so leading to a loop? For example:

/
  Parent
    Child
      SymLink to directory '/Parent'

This would loop if you try to crawl it with File.listFiles().

If so, how can one avoid it, other than not following SymLinks?

Sure, we could check if a link points to a parent directory, but more complicated structures would break that:

/
  Parent1
    SymLink to /Parent2
  Parent2
    SymLink to /Parent1

Right now, the best idea I have is to track all canonical directories already crawled, and refuse to crawl a directory if it has already been crawled, which seems excessive.

Does anyone have any better solutions?

NB: this is part of my attempt to find a solution to Crawling Android File System gets stuck in possible SymLink loop, so can be seen in that context if needed, and more code can be found there.

来源：https://stackoverflow.com/questions/59678418/avoiding-android-symbolic-link-loop