The chroot() and fchroot() functions cause a directory to become the root directory, the starting point for path searches for path names beginning with / (slash). The user's working directory is unaffected by the chroot() and fchroot() functions.
The path argument points to a path name naming a directory. The fildes argument to fchroot() is the open file descriptor of the directory
which is to become the root.
The effective user ID of the process must be super-user to change the root directory. While it is always possible to change to the system root using the fchroot() function, it is not guaranteed to succeed in any other case, even should fildes be valid in all respects.
The ".." entry in the root directory is interpreted to mean the root directory itself. Therefore, ".." cannot be used to access files outside the subtree rooted
at the root directory. Instead, fchroot() can be used to reset the root to a directory that was opened before the root directory was changed.
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