Lists all ports available.

    CLI Example:

    .. code-block:: bash

        salt '*' ports.list_all

    .. warning::

        Takes a while to run, and returns a **LOT** of output

def list_all():
    '''
    Lists all ports available.

    CLI Example:

    .. code-block:: bash

        salt '*' ports.list_all

    .. warning::

        Takes a while to run, and returns a **LOT** of output
    '''
    if 'ports.list_all' not in __context__:
        __context__['ports.list_all'] = []
        for path, dirs, files in salt.utils.path.os_walk('/usr/ports'):
            stripped = path[len('/usr/ports'):]
            if stripped.count('/') != 2 or stripped.endswith('/CVS'):
                continue
            __context__['ports.list_all'].append(stripped[1:])
    return __context__['ports.list_all']