hi dear's,
how i can Run Set-UID shell programs in ubuntu 12.10?
and then, how i can copy /bin/zsh to /tmp, and make it a set-root-uid program with permission 4755????

a shell script itself is not runnable but executed by an interpreter. Therefore the setuid flag has no any meaning on the script file itself. You need to set it on the interpreter (the real binary executable).
set-root-uid can only be set by root.

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a shell script itself is not runnable but executed by an interpreter. Therefore the setuid flag has no any meaning on the script file itself. You need to set it on the interpreter (the real binary executable).
set-root-uid can only be set by root.
how i can set it??
i login as root,

see man chmod, but you have already wrote: chmod 4755 filename should work.

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it's my practice,
2.(2.5 points) Run Set-UID shell programs in Linux, and describe and explain your observations.
a.Login as root, copy /bin/zsh to /tmp, and make it a set-root-uid program with permission 4755. Then login as a normal user, and run /tmp/zsh. Will you get root privilege?
how i can solve it??
whats is ur suggestion??

Will you get root privilege?
What do you need to solve it at all? What is your problem?
What will ls -l /tmp/zsh respond?

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is that this solution correct??
when i want set chmod 4755, use below command:
chmode=4755 (it means -r--rwxr-x)
ad for copy /bin/zsh to /tmp, i use blow command:
cp /bin/zsh /tmp

first do the cp
then check it with stat

now use the chmod command on /tmp/zsh, and re-check with stat

note any differences

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goldengriff-VPCF126FM% cp /bin/zsh /tmp
cp: cannot create regular file `/tmp/zsh': Permission denied
goldengriff-VPCF126FM% su
Password:
root@goldengriff-VPCF126FM:/home/goldengriff# cp /bin/zsh /tmp
cp: cannot create regular file `/tmp/zsh': Text file busy
why??

looks like you already copied zsh to /tmp/ and you are currently running it

I have no idea how many times you have opened it

if you are doing this in X ( gnome or what ever )
close the terminal and then open a new one

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i change chmode with below command:
chmode:5455
and when get the state it's premission not changed??
why??
notice that i close all terminal windows and open new one.
see below command history:
goldengriff-VPCF126FM# /tmp/zsh
goldengriff-VPCF126FM# stat /tmp/zsh
File: `/tmp/zsh'
Size: 688704 Blocks: 1352 IO Block: 4096 regular file
Device: 805h/2053d Inode: 393333 Links: 1
Access: (0755/-rwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2013-11-08 12:44:24.518815236 -0500
Modify: 2013-11-08 12:43:00.826816289 -0500
Change: 2013-11-08 12:43:00.826816289 -0500
Birth: -
goldengriff-VPCF126FM# chmod=4755
goldengriff-VPCF126FM# stat /tmp/zsh
File: `/tmp/zsh'
Size: 688704 Blocks: 1352 IO Block: 4096 regular file
Device: 805h/2053d Inode: 393333 Links: 1
Access: (0755/-rwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2013-11-08 12:44:24.518815236 -0500
Modify: 2013-11-08 12:43:00.826816289 -0500
Change: 2013-11-08 12:43:00.826816289 -0500
Birth: -

thanks for ur attention

you get 4755

you didn't do anything to /tmp/zsh, you just set a variable

please use code tags to make things more readable

[code]
code or output here
[/code]

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thanks