User spock
belongs to groups human
and vulcan
.
File holo
is owned by user root
and by group vulcan
. Its permissions are rwxrwx---
(770).
Process tractor
is started by user spock
, and has uid spock
and primary gid human
.
Will tractor
automatically have access to holo
, or will it have to explicitly request the supplemental group permissions of spock
via an initgroups
call?
The comment here says that it has to be designed to make an explicit request, but the credentials manpage does not mention anything like that and seems (to me) to imply that the supplemental-group checking is automatically done by the OS.