?
Solved

what does this command mean "sudo su - -s /bin/bash jenkins"

Posted on 2016-07-15
3
Medium Priority
?
542 Views
Last Modified: 2016-07-15
I couldn't understand what this command does "sudo su - -s /bin/bash jenkins". Is it log in as jenkins user under the current shell?



root@monitor:/home/jyu$ su - jenkins
su: user - does not exist
root@monitor:/home/jyu$ cat /etc/passwd | grep jenkins
root@monitor:/home/jyu$ sudo su - -s /bin/bash jenkins
Last login: Fri Jul 15 17:17:09 UTC 2016 on pts/1
[jenkins@monitor ~]$ whoami
jenkins
[jenkins@monitor ~]$ ls -alth
total 56K
-rw------- 1 jenkins jenkins 8.5K Jul 15 17:44 .bash_history
drwx------ 2 jenkins jenkins 4.0K Jul 15 16:55 .ssh
drwxr-xr-x 4 jenkins jenkins 4.0K Jul 15 16:55 .
-rw------- 1 jenkins jenkins  11K Jul 15 16:55 .viminfo
drwxr-xr-x 8 root    root    4.0K May 27 22:26 ..
drwxr-xr-x 3 jenkins jenkins 4.0K Jul  8  2014 .java
-rw-r--r-- 1 jenkins jenkins   18 Jul  3  2014 .bash_logout
-rw-r--r-- 1 jenkins jenkins  124 Jul  3  2014 .bashrc
-rw-r--r-- 1 jenkins jenkins  171 Jul  3  2014 .kshrc
-rw-r--r-- 1 jenkins jenkins  176 Jul  3  2014 .bash_profile
[jenkins@monitor ~]$
0
Comment
Question by:Jason Yu
  • 2
3 Comments
 
LVL 68

Accepted Solution

by:
woolmilkporc earned 2000 total points
ID: 41713260
You're using "sudo" to run the command "su" (substitute user) as root, with the parameters
"-" (start a login shell),
"-s /bin/bash" (use /bin/bash instead of the default shell)
"jenkins" (substitute user jenkins).

So yes, basically you're logging in as jenkins, starting bash as a login shell.

I assume that "su - jenkins" doesn't work saying "user - does not exist" because in your environment "su" is already an alias for "su -".

Run "alias su" to verify"

"su" works after "sudo" because sudo doesn't observe alias settings.
0
 

Author Comment

by:Jason Yu
ID: 41713267
Yes, you are right. In my environment, su is an alias of "su -".

root@monitor:/home/jyu$ alias su
alias su='su -'
root@monitor:/home/jyu$
0
 
LVL 68

Expert Comment

by:woolmilkporc
ID: 41713269
That's why "su - jenkins" throws an error.
0

Featured Post

Get quick recovery of individual SharePoint items

Free tool – Veeam Explorer for Microsoft SharePoint, enables fast, easy restores of SharePoint sites, documents, libraries and lists — all with no agents to manage and no additional licenses to buy.

Question has a verified solution.

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

It’s 2016. Password authentication should be dead — or at least close to dying. But, unfortunately, it has not traversed Quagga stage yet. Using password authentication is like laundering hotel guest linens with a washboard — it’s Passé.
Google Drive is extremely cheap offsite storage, and it's even possible to get extra storage for free for two years.  You can use the free account 15GB, and if you have an Android device..when you install Google Drive for the first time it will give…
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
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…
Suggested Courses
Course of the Month12 days, 18 hours left to enroll

579 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