`cat` is short for conCATenate. Here it is being used to concatenate files. This is the canonical useful use of cat.

The problem with that example is parsing `ls` output.

> The problem with that example is parsing `ls` output.

Yeah, I left that alone to keep things simpler and was assuming `ls` was simply being used as short-hand for "some unspecified approach to outputting file names". In a context where hard-to-handle filenames are possible, you'd of course need to do something a little more robust.

Yes, that's what i was getting at. The use of `cat` isn't useless (for once) — the use of `ls` and `xargs` is.

so, how to avoid parsing ls? maybe use cat *, or something?

It really depends on what you are trying to accomplish.

`cat -- *` might be the right choice. Maybe `find . -maxdepth 1 -type f -exec cat -- {} +`