not able to login in ubuntu box with root password

Question

i have ubuntu 10.04 on my sytem, i run command apt-get install csh on the system and try to change the shell by command chsh -s but now the prob is when i try to login the system by ssh i am not able to login by any user account except one and try to change the user su - root it is showing cannot execute c: no such file or directory and look in the /etc/passwd file for root account in shell field C is written in place of /bin/sh help me out to restore the settings

Answer 1

Boot live media.

Make sure your local HD is mounted by browsing for it in nautilus.

Open a terminal: CTL + ALT + T

Get root and change it to whatever shell you want:

sudo su
cd /media/partitionname/etc/
nano passwd

navigate to the root line which you say looks like this:

root:x:0:0:root:/root:C  

make it look like this to restore default:

root:x:0:0:root:/root:/bin/bash  

Press CTL+X then Y then Enter
It should save. Now type:

cd /
sync
exit
exit

Unmount the drive with the eject button in the nautilus window and reboot.

Easy peasy.

Now that it's correct you're able to log in as long as you don't run chsh -s c again. If you want to change a user's shell you specify the full path to the shell as expressed in /etc/shells like chsh -s /bin/csh NOT this chsh -s c