Revert chsh changes

[Taurian]

Hi All,

I have accidently changed the shell using chsh of user prdadm. Now the environment variables are gone and nothing is working via the user.

Please advise on how to revert these changes. I have a Data Protector backup. Which files should I restore in order to gain the functionality back?

[Bill Hassell]

chsh simply changes the shell. Run chsh to change it back to the original shell. This would be a common problem changing the shell from ksh or sh to something totally incompatible like csh.

chsh prdadm /usr/bin/sh

[Taurian]

Hi Bill,

Already tried "chmod prdadm /usr/bin/sh", but it's not working.

[Taurian]

I am actually getting the error: ".profile[40]: SHLIB_PATH: Parameter not set." when I log in to prdadm user.

Also, I am failing to run sqlplus, due to which other problems are arising.

[James R. Ferguson]

Hi:

> Already tried "chmod prdadm /usr/bin/sh", but it's not working.

Re-read Bill's post. You need to use 'chsh' not 'chmod'.

Another way is, as root, edit the 'prdadm' account in '/etc/passwd' and specify '/usr/bin/sh' as the login shell.

Regards!

...JRF...

[Steven Schweda]

> chsh prdadm /usr/bin/sh

> Already tried "chmod prdadm /usr/bin/sh",
> but it's not working.

"chsh" and "chmod" are spelled differently
for a reason.

"It's not working" is not a useful problem
description. It does not say what happened
when you tried this (wrong) command.

[Taurian]

TYPO mistake guys! I meant to say chsh not chmod. I tried the chsh command, not chmod.

Already told you the error I am getting. The user prdadm does not recognise sqlplus command, and in turn SAP startup is failing.

[Bill Hassell]

Perhaps you can tell us what shell you specified for the user? What is the user's shell now?

The environment variables are normally set with the user's profile and for sane shells like POSIX and ksh, that would be .profile, possibly .kshrc. To see what the user has right now, use this command:

awk -F: '/prdadm/{print $NF}' /etc/passwd

[Dennis Handly]

>Which files should I restore in order to gain the functionality back?

This should be as simple as restoring /etc/passwd (if system isn't trusted).

Of course, have you made any other changes to that file?

[Steven Schweda]

> [...] I tried the chsh command, not chmod.

And then what happened? Did you get the
user's shell changed back to the right one?

> Already told you the error I am getting.

When you did what, exactly?

As usual, showing actual commands with their
actual output can be more helpful than vague
descriptions or interpretations. And using
copy+paste can be more reliable than trying
to do it manually.

[Tor-Arne Nostdal · Accepted solution]

Hi Taurian
The simplest for you would be to have your system administrator (root user), to change your login shell...

It seems as you have changed the login shell from cshrc perhaps to sh/ksh.

csh reads .cshrc file to set you environment
sh/ksh reads your .profile to do this

Now, when switching shell - you seem to have an error in .profile which terminate the processing of defining your environment correctly, or forking new shells.

The mess relate to the error given when parsing the .profile - so you need to get this corrected - and again... since you seem a bit unfamiliare with unix I suggest you get the root user to do this.

Should I pick a guess - you have a .profile who try to source several other environment files - and have syntax error in one of them.
... could even be a SAP system ;)

An alternativ could be to move away the current .profile and replace with a simple template file, just so that you can run the chsh command

/Tor-Arne

[Taurian]

Hi Everyone,

Thanks for all your help. Sorry that I was in a rush yesterday that's why I could copy/paste the commands.

Anyways, Tor-Arne's reply was the best and right on the mark, although I am not that much unfamiliar with UNIX. Everyone needs a little help here and there.

Anywho. My original shell was apparently "csh". Which I changed to "ksh" and so it was having trouble processing the .profile file as Tor-Arne put it. I then changed the shell to "sh", think that it was the original shell. But still the .profile was not being processed properly.

Now with Tor-Arne's help, I've restored the original "csh" shell. There are lots of variables being set in the ".cshrc" file.

Now the system behaviour is back to normal.

[Taurian]

Read Tor-Arne's post and my last comments for the solution.

[Bill Hassell]

Just to clarify the situation:

This user had a non-standard shell, csh in this case. That means that all the customization you required was never in .profile (the standard for POSIX and ksh) so all the suggestions would not work until you changed back to /usr/bin/csh as the shell.

So for any user that is runing csh, you should not change the shell until the user translates all the customized .cshrc commands into a .profile, something does require some experience. Otherwise, don't change the shell. This is why most sysadmins reject the use of csh (and relatives like tcsh) for use in Unix servers -- they are incompatible with standard shells.

[Steven Schweda]

> [...] This is why most sysadmins reject the
> use of csh (and relatives like tcsh) for
> use in Unix servers -- they are
> incompatible with standard shells.

"most"? Really? You took a survey? I've
noticed that Spanish is "incompatible with"
English (the "standard" language), too. Do
these "sysadmins" also "reject the use of"
Spanish (and relatives like Portuguese)? Do
they also reject the use of Fortran and
Pascal because they're incompatible with
standard C?

"Different" and "incompatible" are spelled
differently for a reason.