swiftcat is a simple re-implementation of the venerable UNIX cat(1) utility in Swift.
As such, it is no more useful than your system's built-in cat, but I did this as an exercise in writing some reusable Swift code for parsing command-line options and traversing files.
It is mostly compatible with the built-in cat, so you can alias cat=swiftcat and be pretty happy with it. But swiftcat does not implement the -s or -u options, and its output of non-printing characters does not exactly match that of cat.
Building swiftcat requires Xcode 8.x.
In the swiftcat directory, you can type xcodebuild and the product will be built at ./build/Release/swiftcat
Running swiftcat -h will display a a usage hint and summary of available command-line options:
usage: swiftcat [-behntvx] [file ...]
options:
-b, --nonblank-line-numbers Number the non-blank output lines, starting at 1.
-e, --display-eol Display non-printing characters and a dollar sign ('$') at the end of each line.
-h, --help Show this help message.
-n, --line-numbers Number the output lines, starting at 1.
-t, --display-tabs Display non-printing characters, and display tab characters as '^I'.
-v, --display-nonprinting Display non-printing characters so they are visible.
-x, --display-hex Display non-printing characters in hexadecimal notation.
As with cat, if a single dash (-) is specified as a filename, or if no arguments are given, then swiftcat reads from standard input.
Use man cat for more information about what the options mean.
Note that the -h and -x options are extensions not supported by the original cat. The long option names are also not supported by cat.