Function create_user 

pub fn create_user(
    username: &str,
    shell: Option<&str>,
    home: Option<&str>,
) -> ActionSpec

Create a local account (sudo action-steps user-create <name> [...]).

Through the helper rather than sudo useradd directly. A sudoers grant cannot say “this subcommand and no further options”: the arguments are matched as one concatenated string, so /usr/sbin/useradd --create-home * authorised useradd --create-home -o -u 0 -g 0 backdoor too. The helper re-validates the account name, the home directory and the shell, and builds the same useradd --create-home [--home-dir H] [--shell S] <name> argv this function used to build itself.