Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm Precedence: bulk X-No-Archive: yes List-Id: Zsh Workers List List-Post: List-Help: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on f.primenet.com.au X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.0 Date: Fri, 29 Jan 2016 09:18:34 +0000 From: Daniel Shahaf To: Bart Schaefer Cc: zsh-workers@zsh.org Subject: Re: [PATCH] typeset: set $? on incidental error Message-ID: <20160129091834.GA8420@tarsus.local2> References: <20160123235300.GC20278@tarsus.local2> <56A445E0.50706@gmx.com> <20160126225008.GA4731@tarsus.local2> <160126201724.ZM2552@torch.brasslantern.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <160126201724.ZM2552@torch.brasslantern.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Seq: zsh-workers 37831 Bart Schaefer wrote on Tue, Jan 26, 2016 at 20:17:24 -0800: > On Jan 26, 10:50pm, Daniel Shahaf wrote: > } > } If existing typesets always exit zero in the circumstance that the patch > } proposes to change, no code would be broken by this change (no existing > } code, no new zsh-targeted code, no new ksh-targeted code), except for > } new ksh-targeted code written by zsh users who won't be aware of this > } difference. > > This is not true. Scripts using "setopt errexit" or "setopt errreturn" > or "set -e" will fail in ways they did not fail before. Scripts using errexit would have a new early-out failure mode. I think taking the new early-out would, at least in some cases, be the right thing to do: it may be better to abort than to process invalid or incomplete data. I agree that it might be a bug in other cases. All that said, I suppose we may as well stop here: it's clear the original patch isn't on the verge of being applied. How about a docs patch instead, to point out the difference in behaviour? — diff --git a/Doc/Zsh/builtins.yo b/Doc/Zsh/builtins.yo index fb630a7..6e3d146 100644 --- a/Doc/Zsh/builtins.yo +++ b/Doc/Zsh/builtins.yo @@ -1826,6 +1826,23 @@ reserved word interface for tt(typeset) may cause problems with the output of `tt(typeset -p)', which assumes the reserved word interface is available in order to restore array and associative array values. +Unlike parameter assignment statements, tt(typeset)'s exit status on an +assignment that involves a command substitution does not reflect the exit +status of the command substitution. Therefore, to test for an error in +a command substitution, separate the declaration of the parameter from its +initialization: + +example(# WRONG +typeset var1=$(exit 1) || echo "Trouble with var1" + +# RIGHT +typeset var1 && var1=$(exit 1) || echo "Trouble with var1" +) + +To initialize a parameter var(param) to a command output and mark it readonly, +use tt(typeset -r )var(param) or tt(readonly )var(param) after the parameter +assignment statement. + If the shell option tt(TYPESET_SILENT) is not set, for each remaining var(name) that refers to a parameter that is already set, the name and value of the parameter are printed in the form of an assignment. Cheers, Daniel