[Help] Filesystem questions

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1
  1. Does Redox have a predefined system-wide cache directory, like /var/cache on Unix?
  2. Does Redox have a predefined location for shared memory or just an already mounted “ramdisk”?
    Like /dev/shm or /run/shm on Linux?

How could one query for these?
For example, if I want to get the home_dir and temp_dir, these are supported directly in the Rust std:

use std::env;
let _ = env::home_dir();
let _ = env::temp_dir();