/etc/shells
The shells file contains a list of
login shells on the system. Applications use this file to determine
whether a shell is valid. For each shell a single line should be
present, consisting of the shell's path, relative to root.
For example, this file is consulted by chsh to
determine whether a normal user may change the login shell for her
own account. If the command name is not listed, the user will be denied of
change.
It is a requirement for applications such as
GDM which does not populate the face browser if it
can't find /etc/shells or FTP
daemons which traditionally disallow access to users with shells not
included in this file.
cat > /etc/shells << "EOF"
# Begin /etc/shells
/bin/sh
/bin/bash
# End /etc/shells
EOF