Tech blog writers, please stop invoking the "UNIX philosophy". It's always used as a pseudo-technical argument replacement by people with subjective opinions about why software X has too many useful features.
However, parsing the output of ls is generally a bad idea, as it's meant for human consumption, so ls breaks another tenet: It isn't very composable, as it is difficult to use it in a pipeline, even though it should be a prototypical source program.
last week i discovered the `-delete` flag. For years, i had been doing `find <stuff> | xargs -rm` instead.
I agree it's a bad idea (or if you do, at the very least make sure you're calling out to /bin/ls...), but it certainly happens.
Have a look at libxo, which tries to fix this exact issue. FreeBSD adopting it in the base system is encouraging. I hope Linux follows suit, as well.
The phrase "Unix Philosophy" is a concrete, functioning example of compositionality.
Git is a pretty heavyweight tool and many of its commands are not compositional or built up from many smaller functional units. Git repos also do not compose, which is a significant flaw.
One way to cast the ideological stance of the Unix philosophy is "simplicity of implementation at all costs"; the costs include memory unsafety, poor performance (of pipelines and shell scripts), code duplication, race conditions (look at the filesystem, a vast blob of global mutable state!). It's time we start fixing these problems and abandon the mistakes of Unix. Yes, composition is important, but you don't have to sacrifice so terribly much to get it.
Perhaps there is a better concrete example I haven't thought of. I'm curious to know what you think would be a better communication tool (this a serious question, I'm not baiting an argument).