[C2hs] How to use withCStringLen?

[Magicloud Magiclouds]

Hi, thanks for the reply. I did not mean that I do not know how to use
the function this way. For example,
{#fun foo
  { `String' -- string
  , `Int' } -- string length
  -> IO () #}
Where should I put the withCStringLen*?

2009/11/24 Thomas DuBuisson <thomas.dubuisson at gmail.com>:
> This isn't part of c2hs but part of Haskells FFI.
>
> I suggest you see:
> http://haskell.org/ghc/docs/latest/html/libraries/base/Foreign-C-String.html#v:withCStringLen
>
> Basically, if you need to call a C routine but your argument for it is
> a Haskell String then you can convert the Haskell String to a C string
> before passing:
>
> withCStringLen "c2hs has nothing to do with this" ( \(strPtr, strLen) ->
>            some_imported_c_function strPtr strLen)
>
> As for the code being different in c2hs - its the same except where
> you are using special c2hs macros {# ... #}.  If you haven't already
> seen the tutorial [1], I suggest you read that as a start.  Also, its
> easier to help if you include the code you mention.
>
> Cheers,
> Thomas
>
> [1] http://www.cse.unsw.edu.au/~chak/haskell/c2hs/docu/
>
> On Tue, Nov 24, 2009 at 3:23 AM, Magicloud Magiclouds
> <magicloud.magiclouds at gmail.com> wrote:
>> Hi,
>>  I am new to c2hs, while learning and trying it out, I am confused on
>> how to use withCStringLen.
>>  Well, I mean how to use it in .chs file, since the code style is a
>> little different from .hs.
>> Thanks.
>> --
>> 竹密岂妨流水过
>> 山高哪阻野云飞
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>



-- 
竹密岂妨流水过
山高哪阻野云飞