Hi! Gary Vaughn pointed me at gnulib for portability experts. I've been working on some portable shell scripting material. I'm trying to track down the details of a couple of "some systems can't..." comments from the Autoconf documentation, because I haven't been able to find any such systems.
I am looking for systems on which the following *do not* work: unset "$@" (expanding to null, not an empty string, when no positional parameters) shift N getopts set -- args I had been using Solaris's shell as the "oldest shell I can still find", but all of these work in it. (As is so often the case, "portable" is not exactly a boolean; what I want to be able to do is tell people not just that there exists a machine where one of these doesn't work, but what it might be, so they can make informed decisions about it.) -s
