HowTo: Identify Valid Login Shells

Here's a quick tip on listing out and identifying all the shells available from a Fedora box.

This file is also responsible for keep a record of all available and valid login shells root can delegate to a particular system account. This file is also being consulted by other programs to determine the type of user account trying to login into the system.

To list out all valid login shells, simply

# cat /etc/shells
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/bin/sh
/bin/bash
/sbin/nologin
/bin/zsh
/bin/ftpsh
/usr/local/cpanel/bin/jailshell
/usr/local/cpanel/bin/noshell
/dev/null
/bin/ksh
/bin/tcsh
/bin/csh
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The above results should be similar from any other linux /etc/shells file.

A few daemon services of application that consults this file are FTP, SSH, TFTP and more.

Additionally, a super user root cannot create user and designate it with non-existing login shell type from /etc/shells file.