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UID/GID on Executable: Effective vs. Real UID concept

I wrote a short C++ program that only receives an input value (basically cin >> a ;). I enabled UID on it. So ls -l shows:
-rwsr-xr-x 1 root root 6058 Sep 15 09:50 prog

Now I executed it as "test" user and checked the real vs. effective UID as under:
ps -eo cmd,ruser,euser,ruid,euid,pid | grep prog | grep -v grep
./prog test root 501 0 14251

Just as I expected, real userid is 501(test) and effective uid is 0(root).

So far so good.

Now I tried to do the same using a shell script. A bash script called script which should do the same thing but it doesn't. Why? Is there a way to see it working in a shell script.

-rwsr-xr-x 1 root root 5 Sep 15 09:29 script

ps -eo cmd,ruser,euser,ruid,euid,pid | grep 14328
bash test test 501 501 14328

Second, will the script work as root or as user test?

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woolmilkporc

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jlar310

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farzanj

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I ran it on Red Hat Linux (RHEL5.5).
Second, please clarify if effective uid/gid the one that is checked for determining the access/permissions. Does real uid/gid ever matter at all?

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woolmilkporc

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woolmilkporc

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