Linux uses the file system user id (fsuid
) instead of the effective user ID (euid
), and the file system group ID (fsgid
) instead of the effective group ID (egid
) in permission checks.
Is Linux the only operating system in the Unix-like/Unix category of operating systems that uses the fsuid
and the fsgid
? for example, do operating systems like BSD, macOS, Solaris use the fsuid
and the fsgid
?