Set uid

[brian_31]

Hi Team:

I need to change the permission on a binary from
---S--S--x sproot
to s (small s). I think there is a difference between the S ans s in setuid and setgid. Can someone help here to understand the difference and also suggest the method to change the permission to may be ---s--s--x. Please help.

Thanks
Brian.

[Sajid_1 · Accepted solution]

hello,

there is actually no difference in the setguid and setuid values. The difference in S and s is the 'x' value. If you have both 'x' (x in 'rwx') and 'S' is set, then when you display, it will list as - 's'. If only 'S' is set without 'x', then it will display 'S'.

HTH

[S.K. Chan]

The "x", executable bit determines whether "S" or "s" will be display. Take for example.
# touch fileA
# chmod 6001 fileA
==> That gives ---S--S--x
# chmod 6111 fileA
==> That gives ---s--s--x

[Sajid_1]

Hi again,

For more explanation, an eg: to try:
# cd /tmp
# touch test
# ls -al test
-rw-rw-rw- ....test
# chmod 4666 test
# ls -al test
-rwSrw-rw-
# chmod 4766 test
# ls -al test
-rwsrw-rw-

Look at the difference between both 'ls' commands

hth,

[Mark Greene_1]

chmod 6111 will set the permissions to --s--s--x which means that the execute and the setuid bits are both set on owner and group.

The upper case "S" is the setuid bit without execute permissions, and the lower case "s" with the setuid bit with execute permissions.

HTH
mark