Show username@host if inside a container

[edouard-lopez]

related: #214

---

• Zsh Feature to display username@host when inside a container.
• Zsh Pull-request and explaination

Testing this feature will prove challenging we run test in container so it's cool

[edouard-lopez]

function _pure_is_inside_container \
    --argument-names cgroup_namespace
    set --query cgroup_namespace[1]; or set cgroup_namespace /proc/1/cgroup

    begin
        test -r $cgroup_namespace
        and string match \
                --quiet \
                --entire \
                --regex '(lxc|docker)' \
            <$cgroup_namespace
    end
    or test $container = "lxc"
end

[jorgebucaran]

@edouard-lopez Useless use of cat.

string match --quiet --entire --regex '(lxc|docker)' </proc/1/cgroup

[edouard-lopez]

done #271