Effective user id can be set using following permission? 4744 Effective group id can be set using following permission? 2666

Hi, guys reading some interview question and I got some interview stuff online. I have posted this stuff due to I am not getting on any other books and sites. So I need some information regarding What is meant by Effective user id and Effective group id. Here are some question and answer are given.

As I know umask for root and normal user are different. Root user Directory 0022 Files 0133

Normal user Directory 0002 files 0113 Ok! As I want to know whether SUID and SGID have its permission value set. I am not getting Kindly some one discuss these question. Thanks Sagar.dalvi@zoho.com

"As I want to know whether SUID and SGID have its permission value set."

Google says,

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2 members found this post helpful.

BW-userx gave you the answers, but there are a couple of things you also need to know. This is a community forum...we aren't going to email you answers to questions; either you participate in the conversations here, or you won't get any answers. Most importantly, you need to consider what's going to happen if you get this job you're interviewing for. If you don't know the answers to the questions asked, then (not to sound nasty), you are not qualified for the job.

Are you going to come to forums for each and every thing you're asked after you're hired??? Do you think your employer isn't going to notice this? BW-userx looked up the answer easily, so when you say you looked 'on any other books and sites', that seems very unlikely.

1 members found this post helpful.

The manual page man chmod is actually very thorough in its description of this concept.

The parameter for this command, if numeric, is actually octal (base-8), which means that each digit ("0".."7") refers to a three-bit group. This was done because each component of a standard permission mask, rwx, is three bits long. The remaining bits in the word were then assigned to various other purposes, including this one.

Consider the task of implementing, say, your home-grown replacement for the passwd command, which of course allows you to change your password. Well, "only root can do this sort of thing!" And you will probably find that this command is a "setuid" program that is owned by root. When this program is run, by any ordinary Jane or Joe, its effective permissions will be those of root. Thus, even though the issuing user (Jane or Joe) has no such powers, the program does. And this is why it can successfully issue the privileged system calls necessary to change Jane or Joe's password.

You should also know about the apropos command. The command, apropos effective, will list all commands which include that word in their man-page title. (The command, whatis, is similar.) Unfortunately these commands are not perfect: they don't attempt to index words in the text. But for that, you can try a web-search for a search-string such as such as linux man effective.