topic Re: ps does not show effective uid in Operating System - HP-UX

ps does not show effective uid

Rohan_7 — Wed, 11 Feb 2004 04:38:43 GMT

Hi,

I am seeing a problem with 'ps' utility when a program changes its effective UID and GID.
It does not show changed effective UID, instead it shows the original (probably real) UID.
Though, the UID change is successful and any file created by the program has owenership of effective UID.

Any explainations to the problem?

I have HP-UX 11.11i.
Attached a sample test program which changes the UID to 'rohan' and waits for input before exit. Following is 'ps' output when the program is waiting,
bash-2.05b# ps -aef|grep test_sw
root 13895 2904 1 14:49:32 pts/td 0:00 grep test_sw
root 13876 14520 0 14:48:45 pts/tg 0:00 ./test_sw_uid

Thanks in advance
Rohan

Re: ps does not show effective uid

G. Vrijhoeven — Wed, 11 Feb 2004 04:42:43 GMT

Hi Rohan,

You could use -u or -U :

-u uidlist Select processes whose effective user ID numbers
or login names are given in uidlist.

-U uidlist (XPG4 Only.) Select processes whose real user ID
numbers or login names are given in uidlist.

HTH,

Gideon

Re: ps does not show effective uid

Rohan_7 — Wed, 11 Feb 2004 04:52:19 GMT

hi,

Thanks for quick response.
Actually, I tried that. But it does not show required process if you specify changed effective UID to -u.
bash-2.05b# ps -u rohan |grep test_sw

No output!

I am running the program as root, so
bash-2.05b# ps -u root |grep test_sw
13876 pts/tg 0:00 test_sw_uid

-Rohan

Re: ps does not show effective uid

Dietmar Konermann — Wed, 11 Feb 2004 04:52:51 GMT

Rohan,

you use the -f option of ps... man ps:

-f
Show columns user, pid, ppid, cpu, stime, tty, time, and args, in that order.

user
The login name of the effective process owner.

EXTERNAL INFLUENCES
Environment Variables
UNIX95 specifies to use the XPG4 behavior for this command. The changes for XPG4 include support for the entire option set specified above and include the following behavioral changes:

+ The uid or user column displayed by -f or -l will display effective user rather than real user.

So, what you are seeing seems to be the expected behaviour. What happens if you set UNIX95?

Best regards...
Dietmar.