Is there a tool(!) to list assigned subuid and subgid values for users?

usermod -v (--add-sub-uids) and usermod -w (--add-sub-gids) can be used to manipulate the subuid and subgid ranges for a user account, but there appears to be no tool that can merely list them. Is there one? At least on my Ubuntu 14.04 box getent doesn't seem to be prepared to handle that information from /etc/subuid and /etc/subgid. Currently I am using a little shell script, using awk for the purpose. ---------- Here's an excerpt from usermod(8): -v, --add-sub-uids FIRST-LAST Add a range of subordinate uids to the users account. [...] -V, --del-sub-uids FIRST-LAST Remove a range of subordinate uids from the users account. [...] -w, --add-sub-gids FIRST-LAST Add a range of subordinate gids to the users account. [...] -W, --del-sub-gids FIRST-LAST Remove a range of subordinate gids from the users account. [...]