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One may: sudo chsh -s /bin/sh or sudo chsh -s /bin/sh user_name

It is understood that the second command changes the shell for the specified user_name but unclear what happens without specifying a user_name and where is that reflected?

Thank you!

AturSams
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1 Answers1

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The command without a user changes the root user:

terrance@terrance-ubuntu:~$ sudo chsh -s /bin/sh
terrance@terrance-ubuntu:~$ cat /etc/passwd | grep "/bin/sh"
root:x:0:0:root:/root:/bin/sh
terrance@terrance-ubuntu:~$ sudo chsh -s /bin/bash
terrance@terrance-ubuntu:~$ cat /etc/passwd | grep "/bin/bash"
root:x:0:0:root:/root:/bin/bash
Terrance
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    So it is essentially like typing sudo chsh -s /bin/bash root ? – AturSams Jan 17 '23 at 08:12
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    @AturSams Correct, it is the same as that. To run the command on your own user, sudo is not needed and neither is your username. – Terrance Jan 17 '23 at 13:00
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    Specifically, using sudo is a bad idea: normal users are limited to shells listed in /etc/shells, so users cannot accidentally lock themselves out by switching to something that isn't a working shell. As root, you can set anything, including something that doesn't work. – Simon Richter Jan 17 '23 at 13:36
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    The reason sudo chsh changes the shell for root is that sudo switches to root, and chsh changes the shell of the current user. – Simon Richter Jan 17 '23 at 13:37
  • @SimonRichter Thanks for clarifying. :) – AturSams Jan 17 '23 at 15:42
  • Which makes quite a bit of sense; chsh without sudo would change the user's own shell. I'm kind of disappointed that on too many linux systems, chsh without sudo yields an error. – Joshua Jan 17 '23 at 19:32