The gist—as I understand it—is that Unix programs are essentially all equivalent to functions : ([String], TextStream) -> (TextStream, TextStream) which limits how one can tie them together and causes a proliferation of text-processing tools (awk, sed, grep, cut, &c &c) which is not as elegant as functional programming. There are already some Unix command-line tools that work on structured data as mentioned, e.g. jsa…
Just because data is in a text stream doesn't mean it is not structured. Awk is designed to handle structured text for example, the output of most (traditional) Unix tools is 'structured' too (eg., ls and ps). I recommend you read The Unix Programming Environment which gives many illustrations of how the Unix 'text streams' model works in practice. One of the authors of that book and other folks that created Inferno…
Re: Functional programming and the death of the Unix Way
#31Traditional Unix stream processing assumes a specifically line-oriented structure, though, and is somewhat awkward in other cases. The Plan 9 people recognized that, and made some attempts to improve it, for example with Rob Pike's concept of "structural regular expressions" to describe streams that have a different "shape" than an array of lines: http://doc.cat-v.org/bell_labs/structural_regexps/