-``is-breakpoint`` returns 0 if fish is currently showing a prompt in the context of a ``breakpoint`` command. See also the ``fish_breakpoint_prompt`` function.
-``is-login`` returns 0 if fish is a login shell - that is, if fish should perform login tasks such as setting up the PATH. Also ``-l`` or ``--is-login``.
-``filename`` prints the filename of the currently-running script. Also ``current-filename``, ``-f`` or ``--current-filename``. If the current script was called via a symlink, this will return the symlink. If the current script was received by piping into ``source``, then this will return ``-``.
-``basename`` prints just the filename of the running script, without any path-components before.
-``dirname`` prints just the path to the running script, without the actual filename itself. This can be relative to $PWD (including just "."), depending on how the script was called. This is the same as passing the ``filename`` to ``dirname(3)``. It's useful if you want to use other files in the current script's directory or similar.
-``job-control CONTROL_TYPE`` sets the job control type, which can be ``none``, ``full``, or ``interactive``. Also ``-j CONTROL_TYPE`` or ``--job-control CONTROL_TYPE``.
For backwards compatibility most subcommands can also be specified as a long or short option. For example, rather than ``status is-login`` you can type ``status --is-login``. The flag forms are deprecated and may be removed in a future release (but not before fish 4.0).
