nshdoas is based on doas(1). It reads /etc/doas.conf and asks for the root password in case no matching rule exists. This avoids the need to fall back on su(1) and makes it possible to use the 'enable' command when sending nsh commands on standard input.

Introduce an 'interactive_mode' flag which indicates whether standard input is a TTY. This allows nsh to accept commands on standard input for scripting purposes. This will be needed for better integration of at(1). The 'enable' command will not work in non-interactive mode yet. This will be fixed soon.

This will be needed for future work.

If the user begins editing an empty file which corresponds to a file in the /etc/examples directory offer to load this example for editing. Suggested by Tom Smyth. ok tom, chris

Otherwise pfctl -e will never be run during boot, leaving pf disabled by default.

add 'show environment', 'setenv', and 'unsetenv' commands

Being able to manage environment variables from within nsh will be useful, especially if nsh is used as a login shell because nsh's environment is visible to other commands run by nsh. Setting variables can now affect the behaviour of nsh itself. For example, it is possible to set NSH_MANUAL_PAGE from within a running nsh session and the new value will immediately be used by the 'manual' command. This particular variable is only useful to nsh developers themselves but the same mechanism could be used for user-facing variables in the future. If 'show environment' is run without further arguments all variables will be displayed. Otherwise the value of the specified variable will be displayed if the variable exists. All commands support tab-completion for names which already exist in the environment. The 'setenv' commands appends "=" if the name being completed does not yet exist in the environment.

add crontab commands: show crontab, crontab edit, crontab install

ok stsp@