From: Ray Andrews <rayandrews@eastlink.ca>
To: Zsh Users <zsh-users@zsh.org>
Subject: &&||
Date: Mon, 19 Feb 2018 13:12:20 -0800 [thread overview]
Message-ID: <64c5472a-b174-00b6-7ab0-b65d664be675@eastlink.ca> (raw)
function test ()
{
_aaray=`ls`
[ true ] && { print -l "${ _aaray[@]}" | GREP_COLOR='01;33' egrep
--color=always "$1"\
| GREP_COLOR='01;31' egrep --color=always "$2" }\
|| echo bust!
}
$ touch present
$ test present pres
present << two colors.
$ test present pppres
bust!
$ test pppresent p
bust!
When I first did this, I was puzzled by the output, then I wisely
realized that the '||' was in fact responding to the return value of
the failed egrep. At first I did this without the braces and was
content with what happened but I'd expect the braces to force the '||'
to respond to the leading test (which of course never varies here being
true all the time) and thus never give me a 'bust!' regardless of the
egrep return value. I solved the issue by using an 'if/else'
construction but still I'm curious about the above. Is my expectation
mistaken? Within an '&& ||' construction how would I write that to do
as I was expecting -- respond to the truth value of the initial test?
When I use braces in complex '&& ||' situations they always seem to
behave as expected. I do have the niggling feeling my expectation above
is wrong, but I can't quite say why.
next reply other threads:[~2018-02-19 21:12 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-19 21:12 Ray Andrews [this message]
2018-02-19 21:57 ` &&|| Peter Stephenson
2018-02-19 22:47 ` &&|| Ray Andrews
2018-02-20 9:26 ` &&|| Peter Stephenson
2018-02-20 7:54 ` &&|| Ray Andrews
2018-02-20 17:07 ` &&|| Peter Stephenson
2018-02-20 19:24 ` &&|| Ray Andrews
2018-02-20 20:28 ` &&|| Bart Schaefer
2018-02-20 21:45 ` &&|| Ray Andrews
-- strict thread matches above, loose matches on Subject: below --
2004-11-16 13:45 !!:$ keef
2004-11-16 14:22 ` !!:$ Peter Stephenson
2004-11-16 14:31 ` !!:$ Stephane Chazelas
2004-11-16 15:37 ` !!:$ Bart Schaefer
2004-11-16 16:08 ` !!:$ Peter Stephenson
2004-11-17 0:03 ` !!:$ Bart Schaefer
2004-11-17 19:25 ` !!:$ Danek Duvall
2004-11-18 1:10 ` !!:$ Bart Schaefer
2003-07-02 15:06 ?????? JEFF BICKLEY
2003-07-02 19:56 ` ?????? Thorsten Haude
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