* How to substitute empty array element, or empty string
@ 2017-03-22 7:52 ` Sebastian Gniazdowski
2017-03-22 9:52 ` Peter Stephenson
0 siblings, 1 reply; 6+ messages in thread
From: Sebastian Gniazdowski @ 2017-03-22 7:52 UTC (permalink / raw)
To: zsh-users
Hello,
following does not work as expected:
% a=( a "" c ); print -rl -- "${(@)a//*/x}”
x
x
% a=""; print -rl -- "${a//*/x}”
(empty line)
I guess this is inherited from // substitution. I count lines using substitution that matches (*), and it is skipping empty lines, giving wrong line number for following elements.
Is there any solution? I’ve tried (#s), (#s)(#e), *(#e) and nothing.
--
Sebastian Gniazdowski
psprint@zdharma.org
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: How to substitute empty array element, or empty string
2017-03-22 7:52 ` How to substitute empty array element, or empty string Sebastian Gniazdowski
@ 2017-03-22 9:52 ` Peter Stephenson
2017-03-24 11:26 ` Sebastian Gniazdowski
0 siblings, 1 reply; 6+ messages in thread
From: Peter Stephenson @ 2017-03-22 9:52 UTC (permalink / raw)
To: zsh-users
On Wed, 22 Mar 2017 08:52:09 +0100
Sebastian Gniazdowski <psprint@zdharma.org> wrote:
> Hello,
> following does not work as expected:
>
> % a=( a "" c ); print -rl -- "${(@)a//*/x}”
> x
>
> x
This might be one of those "bug" things you sometimes read about for other
projects...
I believe I've sent the version that doesn't loop infinitely.
Other cases in igetmatch() may need adaption.
pws
diff --git a/Src/glob.c b/Src/glob.c
index 0fcb4e1..9ac0ae6 100644
--- a/Src/glob.c
+++ b/Src/glob.c
@@ -2969,7 +2969,7 @@ igetmatch(char **sp, Patprog p, int fl, int n, char *replstr,
do {
/* loop over all matches for global substitution */
matched = 0;
- for (; t < send; ioff++) {
+ for (; t <= send; ioff++) {
/* Find the longest match from this position. */
set_pat_start(p, t-s);
if (pattrylen(p, t, umlen, 0, &patstralloc, ioff)) {
@@ -3018,15 +3018,19 @@ igetmatch(char **sp, Patprog p, int fl, int n, char *replstr,
* which is already marked for replacement.
*/
matched = 1;
+ if (t == send)
+ break;
while (t < mpos) {
ioff++;
umlen -= iincchar(&t, send - t);
}
break;
}
+ if (t == send)
+ break;
umlen -= iincchar(&t, send - t);
}
- } while (matched);
+ } while (matched && t < send);
/*
* check if we can match a blank string, if so do it
* at the start. Goodness knows if this is a good idea
diff --git a/Test/D04parameter.ztst b/Test/D04parameter.ztst
index cb9d50d..99f7dd9 100644
--- a/Test/D04parameter.ztst
+++ b/Test/D04parameter.ztst
@@ -2148,3 +2148,13 @@ F:behavior, see http://austingroupbugs.net/view.php?id=888
[[ ${-} = [[:alnum:]]## ]] || print Failed 2
}
0:$- expansion correctly handles Dash token
+
+ a=(1 "" 3)
+ print -rl -- "${(@)a//*/x}"
+ a=""
+ print -rl -- "${(@)a//*/y}"
+0:Zero-length string match in parameter substitution
+>x
+>x
+>x
+>y
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: How to substitute empty array element, or empty string
2017-03-22 9:52 ` Peter Stephenson
@ 2017-03-24 11:26 ` Sebastian Gniazdowski
2017-03-24 11:49 ` Peter Stephenson
0 siblings, 1 reply; 6+ messages in thread
From: Sebastian Gniazdowski @ 2017-03-24 11:26 UTC (permalink / raw)
To: zsh-users
On 23.03.2017 at 03:04:40, Peter Stephenson (p.stephenson@samsung.com) wrote:
> This might be one of those "bug" things you sometimes read about for other
> projects…
(…)
> + print -rl -- "${(@)a//*/x}"
I'm little thrilled that this goes away from how // "typically" works. In bash // also doesn't match empty element. Maybe it's a Posix thing?
--
Sebastian Gniazdowski
psprint [at] zdharma.org
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: How to substitute empty array element, or empty string
2017-03-24 11:26 ` Sebastian Gniazdowski
@ 2017-03-24 11:49 ` Peter Stephenson
2017-03-25 6:21 ` Sebastian Gniazdowski
0 siblings, 1 reply; 6+ messages in thread
From: Peter Stephenson @ 2017-03-24 11:49 UTC (permalink / raw)
To: zsh-users
On Fri, 24 Mar 2017 12:26:52 +0100
Sebastian Gniazdowski <psprint@zdharma.org> wrote:
> On 23.03.2017 at 03:04:40, Peter Stephenson (p.stephenson@samsung.com) wrote:
> > This might be one of those "bug" things you sometimes read about for other
> > projects…
> (…)
> > + print -rl -- "${(@)a//*/x}"
>
> I'm little thrilled that this goes away from how // "typically"
> works. In bash // also doesn't match empty element. Maybe it's a Posix
> thing?
Hard to see:
[[ '' = * ]] && echo yes
echoes "yes" in bash as well as zsh, so "*" can match an empty string,
and I don't think the / and // operators are standardised.
pws
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: How to substitute empty array element, or empty string
2017-03-24 11:49 ` Peter Stephenson
@ 2017-03-25 6:21 ` Sebastian Gniazdowski
2017-03-25 18:59 ` Chet Ramey
0 siblings, 1 reply; 6+ messages in thread
From: Sebastian Gniazdowski @ 2017-03-25 6:21 UTC (permalink / raw)
To: Peter Stephenson, zsh-users
On 24 marca 2017 at 12:50:43, Peter Stephenson (p.stephenson@samsung.com) wrote:
> [[ '' = * ]] && echo yes
>
> echoes "yes" in bash as well as zsh, so "*" can match an empty string,
> and I don't think the / and // operators are standardised.
Checked that in ksh:
% a=""; echo ${a//*/x}
x
% a=( "" ); echo ${a[@]//*/x}
x
% [[ "" = * ]] && echo yes
yes
It can look like // behavior was bash-driven, and in bash there is the omission for "".
--
Sebastian Gniazdowski
psprint [at] zdharma.org
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: How to substitute empty array element, or empty string
2017-03-25 6:21 ` Sebastian Gniazdowski
@ 2017-03-25 18:59 ` Chet Ramey
0 siblings, 0 replies; 6+ messages in thread
From: Chet Ramey @ 2017-03-25 18:59 UTC (permalink / raw)
To: Sebastian Gniazdowski, Peter Stephenson, zsh-users; +Cc: chet.ramey
On 3/25/17 2:21 AM, Sebastian Gniazdowski wrote:
> On 24 marca 2017 at 12:50:43, Peter Stephenson (p.stephenson@samsung.com) wrote:
>> [[ '' = * ]] && echo yes
>>
>> echoes "yes" in bash as well as zsh, so "*" can match an empty string,
>> and I don't think the / and // operators are standardised.
>
> Checked that in ksh:
>
> % a=""; echo ${a//*/x}
> x
> % a=( "" ); echo ${a[@]//*/x}
> x
> % [[ "" = * ]] && echo yes
> yes
>
> It can look like // behavior was bash-driven, and in bash there is the omission for "".
This was changed between bash-4.3 and bash-4.4.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU chet@case.edu http://cnswww.cns.cwru.edu/~chet/
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-03-25 19:09 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2017-03-22 7:52 ` How to substitute empty array element, or empty string Sebastian Gniazdowski
2017-03-22 9:52 ` Peter Stephenson
2017-03-24 11:26 ` Sebastian Gniazdowski
2017-03-24 11:49 ` Peter Stephenson
2017-03-25 6:21 ` Sebastian Gniazdowski
2017-03-25 18:59 ` Chet Ramey
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