Path: csiph.com!optima2.xanadu-bbs.net!xanadu-bbs.net!news.glorb.com!usenet.stanford.edu!not-for-mail From: Chet Ramey Newsgroups: gnu.bash.bug Subject: Re: read and env variables Date: Sun, 11 Oct 2015 13:57:52 -0400 Organization: ITS, Case Western Reserve University Lines: 31 Approved: bug-bash@gnu.org Message-ID: References: Reply-To: chet.ramey@case.edu NNTP-Posting-Host: lists.gnu.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Trace: usenet.stanford.edu 1444586335 6506 208.118.235.17 (11 Oct 2015 17:58:55 GMT) X-Complaints-To: action@cs.stanford.edu Cc: chet.ramey@case.edu To: isabella parakiss , bug-bash Envelope-to: bug-bash@gnu.org User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 In-Reply-To: X-Junkmail-Whitelist: YES (by domain whitelist at mpv1.tis.cwru.edu) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] X-Received-From: 129.22.105.36 X-BeenThere: bug-bash@gnu.org X-Mailman-Version: 2.1.14 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:11618 On 10/10/15 8:09 PM, isabella parakiss wrote: > $ a= read a <<< x # this creates a variable in the current shell > $ declare -p a > declare -- a="x" > > $ b= mapfile b <<< x # this doesn't > $ declare -p b > bash: declare: b: not found > > > Other shells don't seem to agree on what should happen in this case, but > it'd be nice to have a more consistent behavior. This isn't exactly a consistent example. The `read' example uses a scalar variable that's found in the temporary environment, which it promotes to a global variable, whereas the mapfile example attempts to convert a temporary variable to an array. If you used a consistent example, such as a= read -a a <<< x you would find that the two builtins behave identically. I will see if it's reasonable to promote a variable found in the temporary environment to an array variable in the current scope. Chet -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ``Ars longa, vita brevis'' - Hippocrates Chet Ramey, ITS, CWRU chet@case.edu http://cnswww.cns.cwru.edu/~chet/