[amelius]

Not a good idea. Imagine that you invoke some program A that in turn invokes a coreutils program B. Imagine that A has been written before today (in other words, it is not aware of the STDOUT_JSON technique). Since A and B inherit the STDOUT_JSON environment variable, A will receive JSON. But it is not expecting this, so it will probably crash.

[spdustin]

Thanks for that answer, that lead me to learn and understand more about standard streams and file descriptors than I ever cared to before! That's a good thing. :)

So then, what about this approach: since the de-facto standard streams are STDIN, STDOUT and STDERR using file descriptors 0, 1 and 2, respectively, are there three more reserved numbers (I couldn't find any in my google-glance) that could be used for, say, JSONIN, JSONOUT and JSONERR?

I think the heart of the matter is: unless it becomes part of the POSIX standard, is there any hope on agreeing on an informal "UNIX philosophy" sort of approach that would allow coreutils and shell built-ins to accept and pass structured responses in any kind of object form?