Solving "/bin/bash^M: bad interpreter: No such file or directory"

If you are getting errors like "/bin/bash^M: bad interpreter: No such file or directory", then I am a mind-reader and can say that you have edited this script on a Windows system. Error looks like:

# ./mysql_backup.sh
-bash: ./mysql_backup.sh: /bin/bash^M: bad interpreter: No such file or directory

You can solve this error by using "dos2unix" as:

# dos2unix mysql_backup.sh

Changing User Login Shell On Linux

There are many kinds of shells available.I prefer bash shell which is default on Debian Systems.

To see available shells,do:

cat /etc/shells

To change the shell for a user,we have to edit /etc/passwd file and replace the line /bin/shellname to  your preferred shell.

For example, replace /bin/sh to /bin/bash for user to which it is being done.