UNIX for Dummies Questions & Answers

The other question is, if ls shows:
Does it mean any users (not just in group1) can run the script like usr1?
So that's the difference between drwxr-sr-x and drwxr-xr-x?

Thanks!

Read Perderabo's tutorial Unix File Permissions, the section The Setuid and the Setgid Bits explains the difference between s and S. You could also read the Useless Bit Combination? section.

I already read that article before I post my question, but still got confused. The article says, "if the suid bit is set, but the owner execute bit is off, ls will display a capital S in the case."

But as I understand, the purpose to set suid is: although the file is owned by root, other user can run it. If the file's execute bit is off, what's the purpose to set suid?!

I was hoping to get an answer from another expert. If you understand my question, just spend a few minutes to answer it. Don't assume people did not do their basic homework before they post their questions. It's frustrating to see a post sank without getting a contructive answer.

Also, all suid/guid examples I saw are using root as the owner. Now I'm seeing a normal username has suid/guid bits set. Does it work similarly? i.e. If the file is owned by user1, with a suid bit set, then any other users can run the file?
For guid bit set, if the file is owned by group1, then any other groups can run the file?

I spent quite a bit of time on that article and I'm dismayed that you dismiss it with a comment like "The article did NOT answer my question". When you phrase a question like "If the file's execute bit is off", I have to think that that a rereading of my article might be useful. There are three execute bits, not one, and you do not have a case where all three are off. The section "Useless Bit Combination" discusses your question in some depth and none of the files in that section are owned by root. Suid works fine with non-root users, but none of the examples in your questions had anything to do suid. Your examples are sgid, not suid.

Perderabo, sorry I didn't realize you have multiple posts regarding this question. Thanks for the in-depth explanation in your posts and pointing out my errors. I have a much better idea about suid/sgid now.