Re: [TUHS] 4.1c bsd ptrace man entry ("ptrace is unique and arcane")

On Tue, Jun 25, 2019 at 5:46 PM Larry McVoy <lm(a)mcvoy.com> wrote: it's very handy but quite difficult to work with programatically. The output is convenient for humans to parse, not very nice for programs to parse. /proc on linux has no real standard way of outputting things. You get tables, tuples, and lists and some stuff I can't classify (/proc/execdomains, /proc/devices); and, in some cases, some files give you more than one type of thing. Units are not clear for many tables. /proc on linux has far more than just process information, including stuff that has nothing to do with processes (51 things on my current linux, e.g. /proc/mounts). Things are in many cases not self-describing, though lots of /proc have this issue. I do recall (possibly wrongly) at some point in the 2000s there was an effort to stop putting stuff in /proc, but rather in /sys, but that seems to have not worked out. /proc is just too convenient a place, and by convention, lots of stuff lands there. While I was at LANL we did experiment with having /proc come out as s-expressions, which were nicely self describing, composable, easily parsed and operated on, and almost universally disliked b/c humans don't read s-expressions that easily. So that ended. We've been reimplementing Unix commands in Go for about 8 years now and dealing with all the variance in /proc on linux was a headache. You pretty much need a different function for every file in /proc. And all that said, it's handy, so hard to complain about too much.