This is intended to be a very basic subset (for now) of cat that will be
more efficient for general I/O (mainly pipeines between shell functions)
than spawning a process. Benchmarks do show that it is definitely not always
worth the trade off, but those situations are less likely to occur (large
inputs) and, if they do, the author can be aware of it and use a function
that will prevent the builtin from being used (I'll provide that as well,
instead of `command cat`).
I'll be writing an article on this with benchmarks to rationalize and
explain in depth my approach.