Comparing to `htpasswd`, it is currently difficult to add a large quantity of users in a script using the `htdigest` program, even with the `expect`[1] utility. `htdigest` should support options like `htpasswd`'s `-i` in order to solve this issue. [1]: https://forums.gentoo.org/viewtopic-t-424943-start-0.html
Related to https://bz.apache.org/bugzilla/show_bug.cgi?id=51370 , however any approach is fine as long as it is feasible.