iSH is a project created by Theodore Dubois that aims to bring a Linux shell to iOS devices using a usermode x86 emulator. The project is currently available as a TestFlight beta for iOS devices. iSH already comes with some of the standard programs you would expect in a Linux environment such as Vi, wget, zip/unzip, and tar. Transfering files between iSH and iCloud does not appear to be working as of yet, but you can use wget to transfer files to iSH.
Source: https://www.bleepingcomputer.com/news/linux/ish-an-ios-linux-shell-for-your-iphone-or-ipad/