I initially wrote it basically just for giggles, but was rather pleased a few months ago when I realized I could use it for something I actually needed, and it was just the right thing (presenting a mount point that acted as a view of the differences between two rsnapshot-style hard-link trees -- only took a few dozen lines of very simple code).
A scripting language like those you mentioned is great for if you need to run your script on systems you don't control, or you need it to be cross platform, or you'd describe what you're doing as creating software rather than automating tasks.
No scripting language can ever integrate with the host system quite as well as shell scripts can. Sure, shell scripts make it easy to shoot yourself in the foot, but then can't you say the same of at least perl and ruby?
I don't really see many good use cases for this library though. By the time you'd use it you should probably move on to something else.
What is the basis for this? Shell script is a scripting language (more precisely, a set of scripting languages with similar features.) The difference between shell scripting languages and other scripting languages is that the former are optimized around the need to scale down to a convenient line-by-line way to work with the system in a REPL; while the others may support work in a REPL it is not what they are optimized for.
There's no real reason why other scripting languages can't integrate with the system as well as shell languages.
All sarcasm aside, a very interesting idea. I'm not sure what the proper use case is, but I'm sure someone will love this.
That said, unshare(1) now supports `-r` with `-U`, which was the thing I needed.
