Function nvme_get_subsys_attr 

pub unsafe extern "C" fn nvme_get_subsys_attr(
    s: nvme_subsystem_t,
    attr: *const c_char,
) -> *mut c_char

nvme_get_subsys_attr() - Read subsystem sysfs attribute @s: nvme_subsystem_t object @attr: sysfs attribute name

Return: String with the contents of @attr or %NULL in case of an empty value or in case of an error (indicated by non-zero errno code).