usermod:tldr:c0554

This command is used to modify the shell of a user in a Linux/Unix operating system. Here's an explanation of each part of the command:

• sudo: It stands for "SuperUser DO," and it is used to execute the following command with administrative privileges. The user running this command needs to have the necessary privileges to use sudo.
• usermod: It is a command-line tool used to modify user attributes in Linux/Unix systems.
• --shell ${path-to-shell}: This option is used to specify the new shell for the user. The ${path-to-shell} should be replaced with the actual path to the desired shell executable. For example, /bin/bash is a common path to the Bash shell. This option changes the default shell that the user will use when logging in.
• ${username}: This placeholder should be replaced with the actual username for the user whose shell you want to modify. For example, if you want to modify the shell for a user named "john", you would replace ${username} with john.

So overall, this command would modify the shell of a user identified by ${username} to the shell specified by ${path-to-shell}.