Path: csiph.com!goblin2!goblin1!goblin.stu.neva.ru!usenet.stanford.edu!not-for-mail From: Robert Elz Newsgroups: gnu.bash.bug Subject: Re: Unset array doesn't work Date: Mon, 26 Feb 2018 16:31:09 +0700 Lines: 44 Approved: bug-bash@gnu.org Message-ID: References: <790ade74-690f-541c-9ab4-6359917442d0@case.edu> <755d61fa-d2bc-8855-bc30-4388aff40691@gmail.com> NNTP-Posting-Host: lists.gnu.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: usenet.stanford.edu 1519640672 23889 208.118.235.17 (26 Feb 2018 10:24:32 GMT) X-Complaints-To: action@cs.stanford.edu Cc: bug-bash@gnu.org To: chet.ramey@case.edu Envelope-to: bug-bash@gnu.org In-Reply-To: <790ade74-690f-541c-9ab4-6359917442d0@case.edu> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2001:3c8:9009:181::2 X-BeenThere: bug-bash@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Bug reports for the GNU Bourne Again SHell List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Xref: csiph.com gnu.bash.bug:13745 Date: Mon, 12 Feb 2018 09:26:37 -0500 From: Chet Ramey Message-ID: <790ade74-690f-541c-9ab4-6359917442d0@case.edu> | This is bash's dynamic scoping. The visibility of a local variable is | restricted to a function and its children, and `unset' removes the | currently-visible instance. Removing such an instance can `unconver' an | instance in a previous scope. Frankly this is brain dead, unset should not be unlocal (or something equiv) eg: if I have a func myfunc() { local IFS unset IFS # do some code } the very last thing that I want is for the global IFS to apply. The intent is to use the default IFS value, which is what an unset IFS produces, without affecting the current global IFS setting. In this example, I could do IFS=$' \t\n' if I was willing to assume that $'...' support exists (the shell executing the script is not necessarily going to be bash) or I could do IFS=' ' and just hope that survives as written (it would straight from the editor, but who knows when someone else decides that trailing whitespace on lines should all be deleted). Variants to avoid that get even uglier. All the variable modification operations that apply to globals should be able to be applied to local vars, and have the exact same effect. Unsetting a local variable should result in a local variable that is unset. No more, no less. If an unlocal command is needed, add it (either as a new command, or as some option to local or something.) kre