What is "as per"

Usage examples of "as per".

Yet Little Asia was permitted to survive in all its quasi-legal squalor for the same reason that Hong Kong had once been tolerated by communist China: It helped to vitalize the nation's centralized, planned economy.

And the operation that was performed would have been the only chance he had for his intelligence to survive.

All the barriers in his mind have fallen, the way they used to when he was writing (it was one of the reasons he had quit writing novels, not the only one, but a biggie), time's passage slowing as perception grows, widening until it's like being in a Sergio Leone movie where people die the way people swim in underwater ballets.

Tak could have challenged the boy and almost certainly prevailed, but it was perhaps wiser not to do so.