From mohamadoulamine at gmail.com  Tue Apr 29 11:11:46 2014
From: mohamadoulamine at gmail.com (Lamine)
Date: Tue, 29 Apr 2014 13:11:46 +0200
Subject: allocate memory to Char **
Message-ID: <535F88F2.5000706@gmail.com>


Hi,

I want to do write this C code in haskell code, but i have some pb:

int w ;
char **varnames = ccl_new_array (char *, w);

int i;
           for (i = 0; i < w; i++)
             {
               varnames[i] = ccl_new_array (char, 100);
               sprintf (varnames[i], "x%d", i);
             }

I try this code unsing mallocList to (http://lpaste.net/report/712):
mallocList :: [CString] -> IO (Ptr CString)
mallocList xs = do let n = Prelude.length xs
                    p <- mallocBytes (n*100)
                    forM_ (Prelude.zip [0..] xs)
                     (uncurry (pokeByteOff p))
                    return p

let n = sizeOf(undefined :: CString)
            allocaArray w $ \var -> do
                   xs <- peekArray (w*n) var
                   varnames <- mallocList xs

I have an error "segmentation fault(core dumped)".
can someone please help me? Thank you.

Lamine

From hsyl20 at gmail.com  Tue Apr 29 11:58:06 2014
From: hsyl20 at gmail.com (Sylvain Henry)
Date: Tue, 29 Apr 2014 13:58:06 +0200
Subject: allocate memory to Char **
In-Reply-To: <535F88F2.5000706@gmail.com>
References: <535F88F2.5000706@gmail.com>
Message-ID: <CAPmptcUOnJxxv0mE0Phahd-86fMopeXwwSkwdWWCGC_Xuv_nPw@mail.gmail.com>

Hi,

"varnames" is an array of pointers, you cannot allocate it with mallocBytes
(n*100).

Try something like this (not tested):

mallocList :: [String] -> IO (Ptr CString)
mallocList xs = newArray =<< forM xs g
  where
    g x = do
       b <- mallocBytes 100
       pokeCString b x 99
       return b

pokeCString :: CString -> String -> Int -> IO ()
pokeCString dst value maxLen = withCStringLen (take maxLen value) $ uncurry
(copyArray dst)

-Sylvain


2014-04-29 13:11 GMT+02:00 Lamine <mohamadoulamine at gmail.com>:

>
> Hi,
>
> I want to do write this C code in haskell code, but i have some pb:
>
> int w ;
> char **varnames = ccl_new_array (char *, w);
>
> int i;
>           for (i = 0; i < w; i++)
>             {
>               varnames[i] = ccl_new_array (char, 100);
>               sprintf (varnames[i], "x%d", i);
>             }
>
> I try this code unsing mallocList to (http://lpaste.net/report/712):
> mallocList :: [CString] -> IO (Ptr CString)
> mallocList xs = do let n = Prelude.length xs
>                    p <- mallocBytes (n*100)
>                    forM_ (Prelude.zip [0..] xs)
>                     (uncurry (pokeByteOff p))
>                    return p
>
> let n = sizeOf(undefined :: CString)
>            allocaArray w $ \var -> do
>                   xs <- peekArray (w*n) var
>                   varnames <- mallocList xs
>
> I have an error "segmentation fault(core dumped)".
> can someone please help me? Thank you.
>
> Lamine
> _______________________________________________
> FFI mailing list
> FFI at haskell.org
> http://www.haskell.org/mailman/listinfo/ffi
>
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From mohamadoulamine at gmail.com  Tue Apr 29 13:07:54 2014
From: mohamadoulamine at gmail.com (Lamine)
Date: Tue, 29 Apr 2014 15:07:54 +0200
Subject: allocate memory to Char **
In-Reply-To: <535F8D47.80106@henning-thielemann.de>
References: <535F88F2.5000706@gmail.com> <535F8D47.80106@henning-thielemann.de>
Message-ID: <535FA42A.6030108@gmail.com>

I try pokeElemOff but i have same error "segmentation fault(core 
dumped)". Thank for your response!
On 04/29/2014 01:30 PM, Henning Thielemann wrote:
> Am 29.04.2014 13:11, schrieb Lamine:
>
>> I try this code unsing mallocList to (http://lpaste.net/report/712):
>> mallocList :: [CString] -> IO (Ptr CString)
>> mallocList xs = do let n = Prelude.length xs
>>                     p <- mallocBytes (n*100)
>>                     forM_ (Prelude.zip [0..] xs)
>>                      (uncurry (pokeByteOff p))
>
> I guess this must be pokeElemOff.
>
>>                     return p
>>
>> let n = sizeOf(undefined :: CString)
>>             allocaArray w $ \var -> do
>>                    xs <- peekArray (w*n) var
>>                    varnames <- mallocList xs
>>
>> I have an error "segmentation fault(core dumped)".
>> can someone please help me? Thank you.
>


-- 
? Chaque g?n?ration doit, dans un ?tat relatif de captivit?, d?couvrir 
sa mission. Elle a le choix de la remplir ou la trahir?. Frantz Fanon

From mohamadoulamine at gmail.com  Tue Apr 29 13:40:11 2014
From: mohamadoulamine at gmail.com (Lamine)
Date: Tue, 29 Apr 2014 15:40:11 +0200
Subject: allocate memory to Char **
In-Reply-To: <CAPmptcUOnJxxv0mE0Phahd-86fMopeXwwSkwdWWCGC_Xuv_nPw@mail.gmail.com>
References: <535F88F2.5000706@gmail.com>
 <CAPmptcUOnJxxv0mE0Phahd-86fMopeXwwSkwdWWCGC_Xuv_nPw@mail.gmail.com>
Message-ID: <535FABBB.3060209@gmail.com>

Hi Sylvain,
thank you for your response! I try to use  this 2 lines

allocaArray (w*n) $ \var -> do
                   xs <- peekArray (w) var
to code
char **varnames = ccl_new_array (char *, w);

but it return [CString] not a [String]
On 04/29/2014 01:58 PM, Sylvain Henry wrote:
> Hi,
>
> "varnames" is an array of pointers, you cannot allocate it with 
> mallocBytes (n*100).
>
> Try something like this (not tested):
>
> mallocList :: [String] -> IO (Ptr CString)
> mallocList xs = newArray =<< forM xs g
>   where
>     g x = do
>        b <- mallocBytes 100
>        pokeCString b x 99
>        return b
>
> pokeCString :: CString -> String -> Int -> IO ()
> pokeCString dst value maxLen = withCStringLen (take maxLen value) $ 
> uncurry (copyArray dst)
>
> -Sylvain
>
>
> 2014-04-29 13:11 GMT+02:00 Lamine <mohamadoulamine at gmail.com 
> <mailto:mohamadoulamine at gmail.com>>:
>
>
>     Hi,
>
>     I want to do write this C code in haskell code, but i have some pb:
>
>     int w ;
>     char **varnames = ccl_new_array (char *, w);
>
>     int i;
>               for (i = 0; i < w; i++)
>                 {
>                   varnames[i] = ccl_new_array (char, 100);
>                   sprintf (varnames[i], "x%d", i);
>                 }
>
>     I try this code unsing mallocList to (http://lpaste.net/report/712):
>     mallocList :: [CString] -> IO (Ptr CString)
>     mallocList xs = do let n = Prelude.length xs
>                        p <- mallocBytes (n*100)
>                        forM_ (Prelude.zip [0..] xs)
>                         (uncurry (pokeByteOff p))
>                        return p
>
>     let n = sizeOf(undefined :: CString)
>                allocaArray w $ \var -> do
>                       xs <- peekArray (w*n) var
>                       varnames <- mallocList xs
>
>     I have an error "segmentation fault(core dumped)".
>     can someone please help me? Thank you.
>
>     Lamine
>     _______________________________________________
>     FFI mailing list
>     FFI at haskell.org <mailto:FFI at haskell.org>
>     http://www.haskell.org/mailman/listinfo/ffi
>
>


-- 
? Chaque g?n?ration doit, dans un ?tat relatif de captivit?, d?couvrir 
sa mission. Elle a le choix de la remplir ou la trahir?. Frantz Fanon
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From hsyl20 at gmail.com  Tue Apr 29 13:52:30 2014
From: hsyl20 at gmail.com (Sylvain Henry)
Date: Tue, 29 Apr 2014 15:52:30 +0200
Subject: allocate memory to Char **
In-Reply-To: <535FABBB.3060209@gmail.com>
References: <535F88F2.5000706@gmail.com>
 <CAPmptcUOnJxxv0mE0Phahd-86fMopeXwwSkwdWWCGC_Xuv_nPw@mail.gmail.com>
 <535FABBB.3060209@gmail.com>
Message-ID: <CAPmptcVCw3nGg0Qp+ntqNtmBeDu2XgvUNHHODcMZ8oOXK6UG0w@mail.gmail.com>

To create the [String] as in your example, you just have to write:

let names = ["x"++ show i | i <- [0..w-1]]
varnames <- mallocList names

-Sylvain


2014-04-29 15:40 GMT+02:00 Lamine <mohamadoulamine at gmail.com>:

>  Hi Sylvain,
> thank you for your response! I try to use  this 2 lines
>
> allocaArray (w*n) $ \var -> do
>                   xs <- peekArray (w) var
> to code
> char **varnames = ccl_new_array (char *, w);
>
> but it return [CString] not a [String]
>
> On 04/29/2014 01:58 PM, Sylvain Henry wrote:
>
> Hi,
>
> "varnames" is an array of pointers, you cannot allocate it with
> mallocBytes (n*100).
>
> Try something like this (not tested):
>
> mallocList :: [String] -> IO (Ptr CString)
> mallocList xs = newArray =<< forM xs g
>   where
>     g x = do
>        b <- mallocBytes 100
>        pokeCString b x 99
>        return b
>
> pokeCString :: CString -> String -> Int -> IO ()
> pokeCString dst value maxLen = withCStringLen (take maxLen value) $
> uncurry (copyArray dst)
>
> -Sylvain
>
>
> 2014-04-29 13:11 GMT+02:00 Lamine <mohamadoulamine at gmail.com>:
>
>>
>> Hi,
>>
>> I want to do write this C code in haskell code, but i have some pb:
>>
>> int w ;
>> char **varnames = ccl_new_array (char *, w);
>>
>> int i;
>>           for (i = 0; i < w; i++)
>>             {
>>               varnames[i] = ccl_new_array (char, 100);
>>               sprintf (varnames[i], "x%d", i);
>>             }
>>
>> I try this code unsing mallocList to (http://lpaste.net/report/712):
>> mallocList :: [CString] -> IO (Ptr CString)
>> mallocList xs = do let n = Prelude.length xs
>>                    p <- mallocBytes (n*100)
>>                    forM_ (Prelude.zip [0..] xs)
>>                     (uncurry (pokeByteOff p))
>>                    return p
>>
>> let n = sizeOf(undefined :: CString)
>>            allocaArray w $ \var -> do
>>                   xs <- peekArray (w*n) var
>>                   varnames <- mallocList xs
>>
>> I have an error "segmentation fault(core dumped)".
>> can someone please help me? Thank you.
>>
>> Lamine
>> _______________________________________________
>> FFI mailing list
>> FFI at haskell.org
>> http://www.haskell.org/mailman/listinfo/ffi
>>
>
>
>
> --
> ? Chaque g?n?ration doit, dans un ?tat relatif de captivit?, d?couvrir sa
> mission. Elle a le choix de la remplir ou la trahir?. Frantz Fanon
>
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From mohamadoulamine at gmail.com  Tue Apr 29 14:21:18 2014
From: mohamadoulamine at gmail.com (Lamine)
Date: Tue, 29 Apr 2014 16:21:18 +0200
Subject: allocate memory to Char **
In-Reply-To: <CAPmptcVCw3nGg0Qp+ntqNtmBeDu2XgvUNHHODcMZ8oOXK6UG0w@mail.gmail.com>
References: <535F88F2.5000706@gmail.com>	<CAPmptcUOnJxxv0mE0Phahd-86fMopeXwwSkwdWWCGC_Xuv_nPw@mail.gmail.com>	<535FABBB.3060209@gmail.com>
 <CAPmptcVCw3nGg0Qp+ntqNtmBeDu2XgvUNHHODcMZ8oOXK6UG0w@mail.gmail.com>
Message-ID: <535FB55E.4030800@gmail.com>

Thank a lot ! it works!
Lamine.
On 04/29/2014 03:52 PM, Sylvain Henry wrote:
> To create the [String] as in your example, you just have to write:
>
> let names = ["x"++ show i | i <- [0..w-1]]
> varnames <- mallocList names
>
> -Sylvain
>
>
> 2014-04-29 15:40 GMT+02:00 Lamine <mohamadoulamine at gmail.com 
> <mailto:mohamadoulamine at gmail.com>>:
>
>     Hi Sylvain,
>     thank you for your response! I try to use  this 2 lines
>
>     allocaArray (w*n) $ \var -> do
>                       xs <- peekArray (w) var
>     to code
>     char **varnames = ccl_new_array (char *, w);
>
>     but it return [CString] not a [String]
>
>     On 04/29/2014 01:58 PM, Sylvain Henry wrote:
>>     Hi,
>>
>>     "varnames" is an array of pointers, you cannot allocate it with
>>     mallocBytes (n*100).
>>
>>     Try something like this (not tested):
>>
>>     mallocList :: [String] -> IO (Ptr CString)
>>     mallocList xs = newArray =<< forM xs g
>>       where
>>         g x = do
>>            b <- mallocBytes 100
>>            pokeCString b x 99
>>            return b
>>
>>     pokeCString :: CString -> String -> Int -> IO ()
>>     pokeCString dst value maxLen = withCStringLen (take maxLen value)
>>     $ uncurry (copyArray dst)
>>
>>     -Sylvain
>>
>>
>>     2014-04-29 13:11 GMT+02:00 Lamine <mohamadoulamine at gmail.com
>>     <mailto:mohamadoulamine at gmail.com>>:
>>
>>
>>         Hi,
>>
>>         I want to do write this C code in haskell code, but i have
>>         some pb:
>>
>>         int w ;
>>         char **varnames = ccl_new_array (char *, w);
>>
>>         int i;
>>                   for (i = 0; i < w; i++)
>>                     {
>>                       varnames[i] = ccl_new_array (char, 100);
>>                       sprintf (varnames[i], "x%d", i);
>>                     }
>>
>>         I try this code unsing mallocList to
>>         (http://lpaste.net/report/712):
>>         mallocList :: [CString] -> IO (Ptr CString)
>>         mallocList xs = do let n = Prelude.length xs
>>                            p <- mallocBytes (n*100)
>>                            forM_ (Prelude.zip [0..] xs)
>>                             (uncurry (pokeByteOff p))
>>                            return p
>>
>>         let n = sizeOf(undefined :: CString)
>>                    allocaArray w $ \var -> do
>>                           xs <- peekArray (w*n) var
>>                           varnames <- mallocList xs
>>
>>         I have an error "segmentation fault(core dumped)".
>>         can someone please help me? Thank you.
>>
>>         Lamine
>>         _______________________________________________
>>         FFI mailing list
>>         FFI at haskell.org <mailto:FFI at haskell.org>
>>         http://www.haskell.org/mailman/listinfo/ffi
>>
>>
>
>
>     -- 
>     ? Chaque g?n?ration doit, dans un ?tat relatif de captivit?,
>     d?couvrir sa mission. Elle a le choix de la remplir ou la trahir?.
>     Frantz Fanon
>
>


-- 
? Chaque g?n?ration doit, dans un ?tat relatif de captivit?, d?couvrir 
sa mission. Elle a le choix de la remplir ou la trahir?. Frantz Fanon
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