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From:	John (_You_ hide, they seek.) Mackin <john@physiol.su.oz.au>
Date:	Sun, 12 Jul 1992 18:53:55 -0400
To:	The rc Mailing List <rc@hawkwind.utcs.toronto.edu>
Subject: Re: backquote status?
In-Reply-To: <92Jul11.201318edt.2604@groucho.cs.psu.edu>
Message-Id: <199207130853.1648.rc.babap@physiol.su.oz.au>
X-Face: 39seV7n\`#asqOFdx#oj/Uz*lseO_1n9n7rQS;~ve\e`&Z},nU1+>0X^>mg&M.^X$[ez>{F
 k5[Ah<7xBWF<un6={nlL7Om5<0UsuHKjCxs)C$`DP.N'-LLb8=8)"a@d2bG-f7qD2AJ#UZ>-@-ru?&
 @4K4-b`ydd^`(n%Z{

    Is there any way to retrieve the status from a backquote command?
    It seems that assignments (like x=`false) set status=0.  Is that
    a feature?

We really need to put together an rc FAQ.  I'll volunteer to do it,
although I won't be able to start until I get myself properly
established in my new job, which will take some weeks.  This one
has been discussed on the list at least twice already.  If you
look at the grammar, an assignment is a command.  $status
reflects the status of the last command.  The "false" failed,
but the assignment succeeded, so $status is correctly zero.
Yes, it is a little surprising.

If you want the status from the backquoted command, you can do
the usual sh-style trick of putting it on a suitable fd, something
like:

	fred = ` { false; echo $status >[1=2] }

That can be elaborated as needed.  In some cases, the -e command
line option can be used to advantage.  Also, rc will print an
error message if a backquoted command exits on a signal (Byron
once said he wasn't sure if that was a good feature or not --
personally I don't mind it).

OK,
John.