Re: [Zsh bug] function define bug

[Ngô Huy <huynhok.uit@xxxxxxxxx>]

Dear Cuong,

2015-11-25 16:20 GMT+07:00 Cuong Manh Le <cuong.manhle.vn@xxxxxxxxx>:

> Hi Huy,
>
> It's a good point, but in the user perspective, turn off `multifuncdef` is
> not much useful:
>
> $ unsetopt multifuncdef
> $ echo 1 | grep foobar(){ echo 1; }
> zsh: parse error near `()'
>
> You still stuck and can not use `grep`.
>
> The right way to use it from the beginning is quote the grep string
> pattern if it contains any shell meta characters.
>
> Also in zsh documentation
> http://zsh.sourceforge.net/Doc/Release/Options.html#index-MULTIFUNCDEF ,
> it said that:
>
> Multiple function definitions are not often used and can cause obscure
>> errors.
>
>
> Maybe we should add an example to that section.
>
> Best.
>
>
>
> On Wed, Nov 25, 2015 at 4:03 PM, Ngô Huy <huynhok.uit@xxxxxxxxx> wrote:
>
>> Dear Cuong,
>>
>> 2015-11-25 15:49 GMT+07:00 Cuong Manh Le <cuong.manhle.vn@xxxxxxxxx>:
>>
>>> Hi Severus,
>>>
>>> Can you give a demo?
>>>
>>> You can turn off `multì_func_def` but you can always do multiple
>>> function definition with reserved word `function`
>>>
>>> Best.
>>>
>>>
>>> On Wed, Nov 25, 2015 at 11:20 AM, Ngô Huy <huynhok.uit@xxxxxxxxx> wrote:
>>>
>>>> Dear Matthew
>>>>
>>>> 2015-11-25 11:06 GMT+07:00 Matthew Martin <phy1729@xxxxxxxxx>:
>>>>
>>>> > On Tue, Nov 24, 2015 at 9:46 PM, Ngô Huy <huynhok.uit@xxxxxxxxx>
>>>> wrote:
>>>> > > Dear folks,
>>>> > >
>>>> > > I found the problem in zsh define function. Demo
>>>> > >
>>>> > > ls test() { echo "Bug !!!"} && ls && test
>>>> > >
>>>> > > it will print
>>>> > >
>>>> > > Bug !!!
>>>> > > Bug !!!
>>>> >
>>>> >
>>>> > That's expected behaviour. Since MULTI_FUNC_DEF is set by default in
>>>> zsh
>>>> > mode, both ls and test are being defined as functions with the body
>>>> > echo "Bug !!!".
>>>> >
>>>> > % func1 func2 () { echo This is "$0"; }
>>>> > % func1; func2
>>>> > This is func1
>>>> > This is func2
>>>> > % which func{1,2}
>>>> > func1 () {
>>>> >         echo This is "$0"
>>>> > }
>>>> > func2 () {
>>>> >         echo This is "$0"
>>>> > }
>>>> > % unsetopt MULTI_FUNC_DEF
>>>> > % func1 func2 () { echo This is "$0"; }
>>>> > zsh: parse error near `()'
>>>> >
>>>>
>>>> I know this behavior likes advanced programming language but
>>>> multì_func_def
>>>> should be turned off by default, it leads to risky problem when someone
>>>> searchs as grep, ls malicious strings without quote
>>>>
>>>>
>>>> Kind regards,
>>>> Severus
>>>>
>>>
>>> this's just example: cat file | grep foobar(){ rm -rf *}
>> grep wil execute rest of body
>>
>> Kind regards,
>> Severus
>>
>
> I don't see any case we should use multiple function definition. We also
can not cover all problems with this behavior. I think we should disable it
:)

Kind regards,
Severus