From: Han Pingtian <hanpt@linux.vnet.ibm.com>
To: zsh-users@zsh.org
Cc: Bart Schaefer <schaefer@brasslantern.com>,
Ray Andrews <rayandrews@eastlink.ca>
Subject: Re: for loop question
Date: Tue, 4 Nov 2014 10:29:42 +0800 [thread overview]
Message-ID: <20141104022942.GB2871@localhost.localdomain> (raw)
In-Reply-To: <20141104015639.GA2871@localhost.localdomain>
On Tue, Nov 04, 2014 at 09:56:39AM +0800, Han Pingtian wrote:
> On Sun, Nov 02, 2014 at 09:37:13PM +0000, Stephane Chazelas wrote:
> > 2014-11-02 13:00:14 -0800, Bart Schaefer:
> > > > I've fiddled around with various modifications but it seems to dislike "
> > > [ -n "$TLC[i]" ] "
> > > > even though the 'while' loop is happy with it. That expression evaluates
> > > to true or
> > > > false, does it not? So why won't 'for' swallow it?
> > >
> > > The double parents (( )) are special arithmetic syntax. You can't use an
> > > ordinary shell command like "test" ( for which "[" is an alias) inside that
> > > construct.
> >
> > You could with:
> >
> > for ((i=1; (z[$([ -n "$TLC[i]" ])0]),$? == 0; i++))
> > print -ru2 -- $TLC[i]
> >
> What does the (z[$([ -n "$TLC[i]" ])0]) mean, please?
>
I think I have got the meaning of it. The goal is to run
'[ -n "$TLC[i]" ]' in a math context, so embed the testing in the
subscript of 'z[..]'. The 'z' will be explained as a array in this math
context, the value of '$z[...]' is ignored, only the result of
'[ -n "$TLC[i]" ]' is compared with 0.
next prev parent reply other threads:[~2014-11-04 2:39 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-02 20:47 Ray Andrews
2014-11-02 21:00 ` Bart Schaefer
[not found] ` <CAH+w=7aWS0xyS4CXRJBphDjesfUFQOsyJRMaG3RZRxmuj7xkOg__20885.3257158355$1414962125$gmane$org@mail.gmail.com>
2014-11-02 21:37 ` Stephane Chazelas
2014-11-02 22:44 ` Ray Andrews
2014-11-02 22:57 ` Bart Schaefer
2014-11-02 23:24 ` Oliver Kiddle
2014-11-03 0:07 ` Ray Andrews
2014-11-03 1:53 ` Mikael Magnusson
2014-11-03 2:22 ` Ray Andrews
2014-11-03 9:22 ` Mikael Magnusson
2014-11-03 17:26 ` Ray Andrews
2014-11-04 1:56 ` Han Pingtian
2014-11-04 2:29 ` Han Pingtian [this message]
2014-11-04 2:43 ` Bart Schaefer
2014-11-04 4:51 ` Han Pingtian
2014-11-04 6:37 ` Ray Andrews
2014-11-04 7:13 ` Bart Schaefer
2014-11-04 18:00 ` Ray Andrews
[not found] ` <141103184338.ZM32221__48957.5251042426$1415069142$gmane$org@torch.brasslantern.com>
2014-11-04 7:08 ` Stephane Chazelas
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