chsh

chsh [options] [username]

chsh changes a user's login shell, which is the program started when the user logs in via a terminal. The new shell must be listed in /etc/shells unless the change is made by root.Regular users can change their own shell; root can change any user's shell. The change takes effect on the next login. The user is authenticated before the change is made, so a password is required unless run as root.Common use cases include switching between bash, zsh, fish, or other shells. Part of the util-linux package on Linux systems.

-s, --shell shell

Specify the new login shell

List shells from /etc/shells

Display help message

/etc/shells

List of valid login shells. Only shells listed here can be set by non-root users.

The shell must exist as a binary and be listed in /etc/shells. Setting an invalid or non-existent shell can lock users out of their accounts (use usermod -s /bin/bash as root to fix). Changes take effect on next login. On some systems (e.g., macOS), chsh uses a different implementation with slightly different flags.

usermod(8), passwd(1), login(1), bash(1), zsh(1), fish(1)