Users and permissions

لم يُترجم بعد؛ يُعرض باللغة الإنجليزية

Linux knows every user and group by a number. Every file records one owner, one group and nine permission bits: read, write and execute for the owner, the group and everyone else. Follow the kernel as it checks a request: it picks exactly one of the three sets, then says yes or Permission denied. Then change the rules with chmod, read the same bits as the number 640, and see why root skips the check.