On Sunday 18 April 2010 05:05:23 walt wrote: > On 04/17/2010 06:02 PM, Jonathan wrote: > > What does the E in EUID stand for? > > I did a quick Google and found RUID and EUID but I did not find anything > > else. > > Did you really type what you meant? Doesn't make much sense as is, so I > assume there is a typo in there somewhere. > > Have a leisurely browse through /usr/include/unistd.h to answer your > question.
Nice retort :-) But to answer his question The "E" stands for "effective". His apps are running as a normal user with his UID. In kernel-speak they are effectively running with that UID, hence the term EUID. When you run an app with sudo (or any other app that raises priviledges), sudo is SUID so it runs as root, who permits the user's app to run as root. The UID of that running app is 0, but it's launched by a regular user. That's why we have EUID. It's not the same thing as UID. -- alan dot mckinnon at gmail dot com
