Basic stuff here, but this little project illustrates a few things that I want to remember for cross-platform Swift development:

• how to setup a Swift Package Manager project that compiles on macOS and Linux, using build directives to conditionally import Glibc vs Darwin.C

• how to setup a Makefile so you can test building and running on macOS and Linux OS, from the comfort of your macOS command line thanks to Docker

• basic interop between Swift and C-oriented system API, using getline to echo standard input

Things to try:

$ make build_osx
$ make run_osx # then type a line and have it echoed back
$ make build_linux # if you have Docker installed...
$ make run_linux
$ swift package generate-xcodeproj # to edit in Xcode