[bug] Problem with functions -s (string arg) math function & specific input

[bug] Problem with functions -s (string arg) math function & specific input

[Sebastian Gniazdowski]

Hello,
the contents of the string argument seems to be evaluated in some way
(while it shouldn't). Reproducing snippet:

mtest() { print ${#1}; }
functions -s -M mtest 1 1 mtest
input=') &>/dev/null'
(( mtest($input) ))

Output:
0
zsh: bad math expression: operand expected at `>/dev/null...'

-- 
Sebastian Gniazdowski
News: https://twitter.com/ZdharmaI
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Blog: http://zdharma.org

Re: [bug] Problem with functions -s (string arg) math function & specific input

[Bart Schaefer]

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On Sun, Aug 18, 2019, 8:01 PM Sebastian Gniazdowski <sgniazdowski@gmail.com>
wrote:

>
> functions -s -M mtest 1 1 mtest
>

I'm not at a computer where I can confirm this, but I think the order of
options is significant, you have to use

functions -M -s mtest 1 1 mtest

to define a string function.

>

Re: [bug] Problem with functions -s (string arg) math function & specific input

[Sebastian Gniazdowski]

On Mon, 19 Aug 2019 at 03:19, Bart Schaefer <schaefer@brasslantern.com> wrote:
> On Sun, Aug 18, 2019, 8:01 PM Sebastian Gniazdowski <sgniazdowski@gmail.com> wrote:
>> functions -s -M mtest 1 1 mtest
>
> I'm not at a computer where I can confirm this, but I think the order of options is significant, you have to use
>
> functions -M -s mtest 1 1 mtest
>
> to define a string function.

It still reports the same error.
-- 
Sebastian Gniazdowski
News: https://twitter.com/ZdharmaI
IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
Blog: http://zdharma.org

Re: [bug] Problem with functions -s (string arg) math function & specific input

[Stephane Chazelas]

2019-08-19 03:00:24 +0200, Sebastian Gniazdowski:
> Hello,
> the contents of the string argument seems to be evaluated in some way
> (while it shouldn't). Reproducing snippet:
> 
> mtest() { print ${#1}; }
> functions -s -M mtest 1 1 mtest
> input=') &>/dev/null'
> (( mtest($input) ))
> 
> Output:
> 0
> zsh: bad math expression: operand expected at `>/dev/null...'
[...]

Expansions are done first, and then the result evaluated as
an arithmetic expression. That's a POSIX requirement (for
$((...)))

So here, you're evaluating the:

mtest() &>/dev/null

arithmetic expression.

Just like in:

a='1] + b[2'
echo $((b[$a]))

you're evaluating the b[1] + b[2] arithmetic expression.

-- 
Stephane

Re: [bug] Problem with functions -s (string arg) math function & specific input

[Sebastian Gniazdowski]

On Mon, 19 Aug 2019 at 09:01, Stephane Chazelas
<stephane.chazelas@gmail.com> wrote:
> 2019-08-19 03:00:24 +0200, Sebastian Gniazdowski:
> > Hello,
> > the contents of the string argument seems to be evaluated in some way
> > (while it shouldn't). Reproducing snippet:
> >
> > mtest() { print ${#1}; }
> > functions -s -M mtest 1 1 mtest
> > input=') &>/dev/null'
> > (( mtest($input) ))
> >
> > Output:
> > 0
> > zsh: bad math expression: operand expected at `>/dev/null...'
> [...]
>
> Expansions are done first, and then the result evaluated as
> an arithmetic expression. That's a POSIX requirement (for
> $((...)))
>
> So here, you're evaluating the:
>
> mtest() &>/dev/null

So it seems that ${MATCH//\)/\\\)} should suffice to fix this problem,
as it seems that once a string is within parens (correctly), further
expansions are put on hold for the -s functions.
-- 
Sebastian Gniazdowski
News: https://twitter.com/ZdharmaI
IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
Blog: http://zdharma.org

Re: [bug] Problem with functions -s (string arg) math function & specific input

[Sebastian Gniazdowski]

On Mon, 19 Aug 2019 at 11:53, Sebastian Gniazdowski
<sgniazdowski@gmail.com> wrote:
> So it seems that ${MATCH//\)/\\\)} should suffice to fix this problem,
> as it seems that once a string is within parens (correctly), further
> expansions are put on hold for the -s functions.

Quoting of ( is also needed. It doesn't error without it, however it
then includes the closing paren in the string argument.

-- 
Sebastian Gniazdowski
News: https://twitter.com/ZdharmaI
IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
Blog: http://zdharma.org

Re: [bug] Problem with functions -s (string arg) math function & specific input

[Stephane Chazelas]

2019-08-19 11:59:27 +0200, Sebastian Gniazdowski:
> On Mon, 19 Aug 2019 at 11:53, Sebastian Gniazdowski
> <sgniazdowski@gmail.com> wrote:
> > So it seems that ${MATCH//\)/\\\)} should suffice to fix this problem,
> > as it seems that once a string is within parens (correctly), further
> > expansions are put on hold for the -s functions.
> 
> Quoting of ( is also needed. It doesn't error without it, however it
> then includes the closing paren in the string argument.
[...]

It appears so. Or more exactly, you'd need to escape any
unmatched unescaped ( or ). (input='()' is fine).

-- 
Stephane