The Source History of Cat

>>janvdb+(OP)
The cat utility is among the simplest, but once upon a time true was about the simplest possible Unix utility.

    #!/bin/sh

Yes, that's really it. Fire up the shell, get it to exit with 0, which is taken as success. That's all that's really necessary for its spec.

GNU's is around 29 KiB compiled, and it uses some of that to support --version and --help flags. MacOS's is around 17 KiB compiled and ignores flags.

zlacker