Which command shows all defined variables in Bash?

The command that shows all defined variables in Bash is 'set'. When executed without any arguments, 'set' will display a list of all the shell variables and functions that are currently defined in the Bash environment. This includes both environment variables, which are accessible to child processes, and shell variables, which are local to the shell session.

Additionally, 'set' provides detailed information about variables, such as their values, and specifies whether they are exported or local. This makes 'set' a versatile command for examining the configuration of your Bash session. It's especially useful for debugging scripts or understanding the current environment.

Other commands like 'env' are used to display the current environment variables but do not list all defined Bash variables, especially those that are not exported. Meanwhile, 'show' and 'list' are not standard commands in Bash for displaying variables, which further highlights why 'set' is the correct choice for this specific inquiry.