[mkskm]

Here's another function in Fish that incorporates the other suggestions offered in this thread.

    function sudo --description "Execute a command as another user."
        if [ (uname) = "Darwin" ]
            set --local needle "^auth\b.*\bpam_\(reattach\|tid\|watchid\)\.so\$"
            if ! grep $needle --silent /etc/pam.d/sudo && \
                [ -f /usr/local/lib/pam/pam_reattach.so* ] && \
                [ -f /usr/local/lib/pam/pam_watchid.so* ]
            command sudo sh -c "
            cat << EOF >/etc/pam.d/sudo
    auth optional pam_reattach.so
    auth sufficient pam_tid.so
    auth sufficient pam_watchid.so
    \$(grep -v '$needle' /etc/pam.d/sudo)
    EOF"; or return $status
            end
        end
        command sudo $argv
    end