Re: [Zsh bug] function define bug

[Cuong Manh Le <cuong.manhle.vn@xxxxxxxxx>]

Hi Huy,

See this commit
https://github.com/zsh-users/zsh/commit/b4a198cdda3d499af4e2b4f4a2279f98c8d07433
for an example usage.

Best.

On Wed, Nov 25, 2015 at 4:39 PM, Ngô Huy <huynhok.uit@xxxxxxxxx> wrote:

> 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
>