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Old 01-04-2010, 10:51 PM   #1
jcky
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euser and ruser


What are meaning of these ps options , euser and ruser?

Could you please help me to solve the problem?
 
Old 01-04-2010, 11:31 PM   #2
TB0ne
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Quote:
Originally Posted by jcky View Post
What are meaning of these ps options , euser and ruser?

Could you please help me to solve the problem?
Solve what problem??? What are you trying to do, on what version/distro of Linux, and what exactly is the problem??

If you need to know about command options, type in "man ps", and read about them.
 
Old 01-04-2010, 11:33 PM   #3
jschiwal
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There are three user IDs associated with a process. Real user, effective user and saved-set user.

If you run a suid root program, the effective user is root, while the real user is your regular user. A program like passwd allows you to change your own password but not another persons. The program needs to be root to edit /etc/passwd or /etc/shadow, however it also needs to know which user called it.

Another program may need to start out as a system user, switch back to the original user (real user) and later back again as the system user. This is what the saved-set user is for. When a system user executes a command on our behalf, it calls suid to change the effective user ID to our UID. But under these conditions, the saved-set user ID is not changed. After the program (such as a filter is finished) the program runs "geteuid" to change the effective UID back to the system user. This is allowed because the saved set-user-ID is the same system user. This allows a program or service to drop privileges when not needed.
 
  


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