On shells

Here there are some of the commands around (linux) shells that I keep needing and I keep forgetting.

• Finding what shell is in use:

  echo "$SHELL"
  

• Checking what are the installed shells:

  cat /etc/shells
  

• To temporaly changing the shell, enter its name in the command line. For example to temporaly change to tcsh:

  tcsh
  

  Once you are done you can exit the temporary shell

  exit
  

• Changing the default shell to tcsh (this will be operative at the next connection):

  chsh -s /bin/tcsh