?
Solved

RHEL 6 su command question

Posted on 2011-03-22
3
Medium Priority
?
753 Views
Last Modified: 2013-11-17
What is the difference between

su tcn

Open in new window


and

su - tcn

Open in new window


I looked up the man page and it states:

Change the effective user id and group id to that of USER.

-, -l, --login

Open in new window


Doesn't "su tcn" change the user id.  Would this command not change the group id without the dash ?
0
Comment
Question by:Los Angeles1
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 68

Expert Comment

by:woolmilkporc
ID: 35189956
There is a difference between userid/groupid and "effective" userid/groupid.

The effective IDs are only changed with "su -", and also the login profile of the target user is only executed with "su -".

wmp
0
 
LVL 12

Expert Comment

by:upanwar
ID: 35189961
With su you just become that user but home directory will not be changed and it will not read his .bash_profile and .bashrc so env variable set by him will not be available but

With su - it is like you have logged in with that user. home directory will be changed. Path will be set according that user. It will read that users .bash_profile and .bashrc, all custome env variable will be available.
0
 
LVL 68

Accepted Solution

by:
woolmilkporc earned 2000 total points
ID: 35190030
Sorry, seems I've been typing too fast!

I should have written

Only the effective IDs are changed with "su" alone, the login profile of the target user is only executed with "su -".
0

Featured Post

Veeam Disaster Recovery in Microsoft Azure

Veeam PN for Microsoft Azure is a FREE solution designed to simplify and automate the setup of a DR site in Microsoft Azure using lightweight software-defined networking. It reduces the complexity of VPN deployments and is designed for businesses of ALL sizes.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

If you have a server on collocation with the super-fast CPU, that doesn't mean that you get it running at full power. Here is a preamble. When doing inventory of Linux servers, that I'm administering, I've found that some of them are running on l…
Setting up Secure Ubuntu server on VMware 1.      Insert the Ubuntu Server distribution CD or attach the ISO of the CD which is in the “Datastore”. Note that it is important to install the x64 edition on servers, not the X86 editions. 2.      Power on th…
Learn how to get help with Linux/Unix bash shell commands. Use help to read help documents for built in bash shell commands.: Use man to interface with the online reference manuals for shell commands.: Use man to search man pages for unknown command…
Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.
Suggested Courses
Course of the Month12 days, 13 hours left to enroll

777 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question