How to Free All Memory ?

How to Free All Memory ?

Its possible, or only for to all position and clean one by one ?

Yes it's possible, just keep track of the memory you allocate*... Otherwise no it's not, at least not in the portable sense.

* For example:

Code:

---

void * my_malloc(size_t n)
{
  void * ptr = malloc(n);

  if(ptr)
  {
      /* add ptr to an array or linked list or something */
  }

  return ptr;
}

---

It is possible for program to use its own memory management routine...

At the start-up program allocates some big regeon using malloc (or something)
Later - it uses only parts of this regeon by calling some home-made alloc/free procedures...

When work is done - the whole regeon is freed - guarantiing that all the memory is returned to the OS

If you meant if there is a function to free all memory you've allocated so far, then no, there isn't.
There are solutions as vart and zacs7 point out, but they do have their own overhead.

Well it's not so hard actually, as long as you know what you're doing and don't care about screwing up libc allocator (never tested it though, but I do not see any reason why it should not).
On UNIX you have brk/sbrk call. Calling sbrk with 0 as argument will give you the pointer to the current heap (top/bottom? depending on arch supposedly). So at the start of the program call sbrk(0), then later at some point call sbrk(0) again, calculate the difference and call sbrk(difference).

Anyway, although it's possible, I'd never do it that way in real application.

Quote:

---

Originally Posted by bboozzoo

Well it's not so hard actually, as long as you know what you're doing and don't care about screwing up libc allocator (never tested it though, but I do not see any reason why it should not).
On UNIX you have brk/sbrk call. Calling sbrk with 0 as argument will give you the pointer to the current heap (top/bottom? depending on arch supposedly). So at the start of the program call sbrk(0), then later at some point call sbrk(0) again, calculate the difference and call sbrk(difference).

Anyway, although it's possible, I'd never do it that way in real application.

---

That is an almost guaranteed way to crash your system... But yes, that would do the task sergioms is asking for - but not a good idea to do that.

--
Mats

To answer the full question in simple terms: No you can't.

A longer answer is:
Assuming there was a way to say "free everything allocated from the heap", you would potentially cause all sorts of problems. Say for example you use "fopen()" to open a file, and you later on call the "magicalfreeeverythingfunction()" - what happens if you call fread() on your file, and the fopen() called malloc to get its internal buffer? If it doesn't go wrong at that point, it almost certainly WILL go wrong when that memory gets allocated for a different reason, because fread() will overwrite the data in the memory you just allocated.

And whilst sergioms's code may not use fopen, fread, etc, it certainly does use library functions that we do not know exactly what the underlying code does. Functions that allocate and free memory arbitrarily are not required to identify themselves in any particular way. So any attempt to free "all memory" without knowing what it represents is almost certain to cause problems.

--
Mats

My Equipment is crazy
I think it not free memory when I Try.

Because, im all alloc and de-alloc, but sometimes it crash.

Example:

Code:

---

int VcomCmdUser(TCPREADDATA *p)          // Processa as Entradas Recebidas Pelo Usuário. (Obj. Comunicação
{       
        unsigned int iSckMaxBuffer = 128;
       
        if (p->Length >= 4 && p->Length <= iSckMaxBuffer){        // Pelo Menos 4 Caracteres [STX]XX[13][10]
                ProcessaChamado (p->ReadUartChar, p->Length);
                ClearStr (p->ReadUartChar);
        }       
        return 1; 
}

int ProcessaChamado (unsigned char *pPacote, int pLen){
       
        unsigned char *cFuncao;
        unsigned char *cSubFuncao;
        unsigned char *cPacote;
       
        int iPosStart, iPosEnd, iPosTam;
       
        cPacote = malloc (pLen);
        if (cPacote == NULL)
                VcomSendSocket(iUserSocket, "3-ERRO DE ALOCAÇÃO DE MEMÓRIA", 29);       
        else
                //VcomSendSocket(iUserSocket, pPacote, pLen);       
       
        //Separa o Pacote
        iPosStart = strpos (pPacote, cSTX);

        iPosStart++;
       
        iPosEnd = strpos (pPacote, cCR);
       
        iPosTam = iPosEnd - iPosStart;
               
        if((iPosStart >= 0) && (iPosEnd)){
                substring(&pPacote[iPosStart], cPacote, iPosTam);
       
                if(strlen (cPacote) > 0){
                                               
                        substring(&cPacote[0], cFuncao, 2);
                       
                        if (strcmp (cFuncao, "OP") == 0){                                                                // Recebe Ordem de Pesagem
                                substring(&cPacote[3], cSubFuncao, iPosTam - 2);
                                OrdemProducao (cSubFuncao);
                        }
                        else if (strcmp (cFuncao, "OI") == 0){                                                        // Recebe Ordem de Pesagem Item
                                substring(&cPacote[2], cSubFuncao, iPosTam - 2);
                                OrdemProducaoItem (cSubFuncao);
                        }
                        else if (strcmp (cFuncao, "OK") == 0){                                                        // Tratamento de Confirmações
                                substring(&cPacote[2], cSubFuncao, 2);
                                if (strcmp (cSubFuncao, "OP") == 0)        {                                                // Recebe Confirmação de Ordem de Pesagem
                                        EnviaPedidoPC ("OISL", 4);               
                                }
                                else if (strcmp (cSubFuncao, "OI") == 0){                                        // Recebe Confirmação de Ordem de Pesagem Item
                                        //if (iItemID == 1){
                                        lPesoTara = lPeso;
                                        iPesaItem = 1;
                                }
                                else if (strcmp (cSubFuncao, "IR") == 0){                                        // Recebe Confirmação de Entrega de Resposta de Item
                                        EnviaPedidoPC ("OISL", 4);
                                }
                        }
                        else if (strcmp (cFuncao, "FI") == 0){                                                        // Recebe Finaliza Item Indicando que Recebeu Todos Itens da OP
                                        iStepInput0 = 0;
                                        iItemID = 0;
                                        iPesaItem = 0;
                                        EnviaPedidoPC ("OPFI", 4);
                                        EscreveDisplay ("ORDEM CONCLUIDA.........................", 3);
                        }
                        else if (strcmp (cFuncao, "ER") == 0){                                                        // Erro do Objeto de Comunicação
                                iStepInput0 = 0;
                                substring(&cPacote[3], cSubFuncao, iPosTam - 3);
                                EscreveDisplay (cSubFuncao, 3);
                        }
                        else if (strcmp (cFuncao, "CC") == 0){                                                        // Check Connection
                                // CheckConnection, Não faz nada.
                        }
                        else{
                                // Pacote Não Identitificado;
                        }
                }
                else {
                        free (cPacote);
                        return 0;
                }
        }
       
        free (cPacote);
       
        return 1;
}

---

in this function, i send a CC (CheckConnection at each 30 s)
when i receive some of CC
the program crash and send a message indicate alloc not sucessfull.

That indicates memory corruption - which a "free all" function would not solve.
Get a debugger and start debugging!

Quote:

---

Originally Posted by Elysia

That indicates memory corruption - which a "free all" function would not solve.
Get a debugger and start debugging!

---

I love debug,

but this not a pc
is a icp-i7188E3

and, use a Serial RS-232 to communicate with a balance
a serial 485 to send text to a led display
socket to communicate with a listen socket software
and Digital I/O

when the program crash
it closed all outputs, and no send a message about the error.

I think I've pointed out twice (if not three times) that you are not allocating memory for cFuncao and cSubFuncao [variable names from memory] - you also do not really NEED to use allocation here, fixed size arrays should work perfectly fine.

--
Mats

Well the only way to free all memory is to call exit() (or return from main()...), but I'm guessing you don't actually want to free everything... :D

If by free everything, one only needs to free all handles currently owned by the current process or a certain target process, I do not believe that the question is quite as dangerous nor far-fetched as many have made it sound. Perhaps with a little further explanation as to what purpose this would serve may help us better point you in the right direction.

My gut feeling is that you keep running into issues where your program is eating away a great deal of system resources and your solution is to go ahead and deallocate everything. Thus eliminating the leaked memory handles. If this is the case, you probably should find out why you are leaking so much memory. If not, then if you are doing this in the event that malloc() returns NULL and wish to "free all" to hopefully claim memory resources for your own I would say this is an ill-advised application programming strategy. Considering the fact that your user may have important tasks eating up all the memory you can never assume too much about why the user is out of RAM.

-sphynxster.

Yes, freeing all KNOWN pointers is fine - however, that doesn't actually solve the problem of a memory leak that I'm pretty sure is what sergioms was actually referring to - however, I also think that this is not ACTUALLY the problem in this case - it is a case of abusing memory allocated (or constant data strings) elsewhere.

Also, to "close all known handles" requires that you know what those are.

--
Mats

Very true, some mallocs keep a full table of handles internally though. So its reasonable to say that with a keen enough understanding of the internal data structures used you could theoretically free a handle without knowing what it was. At this point we are no longer talking OS specific, we are talking a specific libc or a specific kernel build. It would be an implimentation so specific it would hardly be worth investigating if the initial issue is indeed a mishandled memory leak. I can only leave it up to sergioms to point us in the direction of what he was trying to do.

Code:

---

#include <conio.h>
#include "..\..\lib\7188e.h"

void (far *Reset_Program)(void)=0xFFFF0000L;    //Program start address.

void main(void)
{
    InitLib();
   
    Print("Press any ket to begin\n\r");
    Print("and press any key can reset the program.\n\r");
    Getch();
   
    for(;;)
    {
        if(Kbhit())
        {
            Print("7188E have reseted by software.");
            DelayMs(10);    //Delay 10 ms to wait for all data is sent to COM port.
           
            Reset_Program();    //You can call the function or
                                //replace it by following 3 asam codes.
                     
                                //_asm push 0xffff
                                //_asm push 0
                                //_asm retf
        }
        else
            Print("*"); //Print '*' while the program is running.
    }
}

---

My program reset code, to ICP-i7188 sended by the support.

> but this not a pc
> is a icp-i7188E3
So what part of ProcessaChamado() ABSOLUTELY MUST be run on the target?

I mean, you could (IMO) easily test this on your PC as a console program, by having

Code:

---

int main ( ) {
    printf( "Result=%d\n", ProcessaChamado ("hello", 5) );
}

---

and a whole host of other tests.
You can use the debugger to crawl all over it to make sure there are no leaks and no overruns.

By writing functions which don't depend on the target platform at all, you can very easily test them on your PC.

A set of other functions, you can easily write a library of stub functions.
For example, if you've got a target specific LightLED( int id ); function, you can simply create a stub function for the PC which is simply

Code:

---

void LightLED ( int id ) {
  printf( "LightLED(%d) called\n", id );
}

---

By the time you get your code on the target, you should have a pretty good idea that 95% of it has already been tested.

Quote:

---

Originally Posted by sergioms

I love debug,

but this not a pc
is a icp-i7188E3

and, use a Serial RS-232 to communicate with a balance
a serial 485 to send text to a led display
socket to communicate with a listen socket software
and Digital I/O

when the program crash
it closed all outputs, and no send a message about the error.

---

Have you put some printfs into your program to give you an idea of what is wrong?

Quote:

---

Originally Posted by esbo

Have you put some printfs into your program to give you an idea of what is wrong?

---

when the program crashs, all outputs stop, and stop execution.

Yes but if you do it before certain key areas you may find out the line that's crashing.

ie,

Code:

---

printf("%p\n", (void *) ptr);

ptr->foo = 10;

---

Like Salem says, you can actually simulate most of these interactions on a PC - there are tools for particularly detecting overruns on memory and such things on the PC, which may not exist on your embedded system, so whilst there is a LITTLE bit of extra work required to get the code working on a PC, you will almost certainly regain all of that and more again by finding logical/memory management problems earlier and easier.

--
Mats

Ok, its function is ok at my ICP, whatever, some times next execute it,
the program send to socket ....... when i try to send OPSL.

The functions actual on ICP:

Code:

---

void EscreveDisplay (unsigned char *pMensagem, unsigned int pDelaySec){
 unsigned char cDispPacote [52];
 int iComDisplay = 2;
 unsigned int iLims;
 unsigned int iLenMsg, iLenCont, iContIndex;
 int iBcc;
 
 iDisplaySend = 1;
 if (pDelaySec > 0)
  Delay(pDelaySec * 1000);
 
 iLims  = 46;
 
 cDispPacote [0] = 129;
 cDispPacote [1] = 126;
 cDispPacote [2] = iLims % 256;
 cDispPacote [3] = iLims / 256;
 cDispPacote [4] = 1 % 256;
 cDispPacote [5] = 1 / 256;
 cDispPacote [6] = 0 % 256;
 cDispPacote [7] = 0 / 256;
 cDispPacote [8] = 76;
 cDispPacote [9] = 202;
 
 iLenMsg = strlen (pMensagem);
 if (iLenMsg > 40)
  iLenMsg = 40;
 if (iLenMsg < 40){
  for(iLenCont=iLenMsg; iLenCont<40; iLenCont++)
  strcat (pMensagem, ".");
 }
 
 for(iLenCont=0; iLenCont<40; iLenCont++){
  iContIndex = iLenCont + 10;
  cDispPacote [iContIndex] = pMensagem [iLenCont];
 }
 
 iBcc = cDispPacote [4];
 cDispPacote [50] = iBcc;
 cDispPacote [51] = '\0';
 
 for(iContIndex=0; iContIndex<=51; iContIndex++){
  ToCom (iComDisplay, cDispPacote[iContIndex]);
 }
 
 iDisplaySend=0;
}

---

this function in pc, not is ok, all crazy chars in cDispPacote

I try change to this:

Code:

---

#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void EscreveDisplay (unsigned char *pMensagem, unsigned int pDelaySec);
void main(void)
{
 EscreveDisplay ("SERGIO", 0);
}
void EscreveDisplay (unsigned char *pMensagem, unsigned int pDelaySec){
 unsigned char cDispPacote [52];
 unsigned int iLims;
 unsigned int iLenMsg, iLenCont, iContIndex;
 int iBcc;
 iLims  = 46;
 
 cDispPacote [0] = 129;
 cDispPacote [1] = 126;
 cDispPacote [2] = iLims % 256;
 cDispPacote [3] = iLims / 256;
 cDispPacote [4] = 1 % 256;
 cDispPacote [5] = 1 / 256;
 cDispPacote [6] = 0 % 256;
 cDispPacote [7] = 0 / 256;
 cDispPacote [8] = 76;
 cDispPacote [9] = 202;
 
 iLenMsg = strlen (pMensagem);
 
 for (iLenCont=10; iLenCont<=49; iLenCont++)
  cDispPacote [iLenCont] = '.';
 
 for(iLenCont=0; iLenCont<iLenMsg; iLenCont++){
  iContIndex = iLenCont + 10;
  cDispPacote [iContIndex] = pMensagem [iLenCont];
 }
 
 iBcc = cDispPacote [4];
 cDispPacote [50] = iBcc;
 cDispPacote [51] = '\0';
 
 printf ("Linha 1: \n");
 
 for(iContIndex=0; iContIndex<=51; iContIndex++){
  printf ("[%i] %c\n",iContIndex,cDispPacote[iContIndex]);
 }
 
 printf ("\n");
 getch ();
}

---

Like some this, but in pc is ok, but no in my ICP
:S

Well, this is definitely WRONG:

Code:

---

if (iLenMsg < 40){
  for(iLenCont=iLenMsg; iLenCont<40; iLenCont++)
  strcat (pMensagem, ".");
 }

---

[By the way, you don't actually need the if (iLenMsg...) - it is done as part of the for-loop, so you won't enter the loop if it's iLenMsg >= 40.]

--
Mats

Code:

---

void EscreveDisplay (unsigned char *pMensagem, unsigned int pDelaySec){
        unsigned char cDispPacote [52];
        int iComDisplay = 2;
        unsigned int iLims;
        unsigned int iLenMsg, iLenCont, iContIndex;
        int iBcc;
       
        iDisplaySend = 1;
        if (pDelaySec > 0)
                Delay(pDelaySec * 1000);
       
        iLims  = 46;
       
        cDispPacote [0] = 129;
        cDispPacote [1] = 126;
        cDispPacote [2] = iLims % 256;
        cDispPacote [3] = iLims / 256;
        cDispPacote [4] = 1 % 256;
        cDispPacote [5] = 1 / 256;
        cDispPacote [6] = 0 % 256;
        cDispPacote [7] = 0 / 256;
        cDispPacote [8] = 76;
        cDispPacote [9] = 202;
       
        iLenMsg = strlen (pMensagem);
 
        for (iLenCont=10; iLenCont<=49; iLenCont++)
                cDispPacote [iLenCont] = '.';
       
        for(iLenCont=0; iLenCont<iLenMsg - 1; iLenCont++){
                iContIndex = iLenCont + 10;
                cDispPacote [iContIndex] = pMensagem [iLenCont];
        }
       
        iBcc = cDispPacote [4];
        cDispPacote [50] = iBcc;
        cDispPacote [51] = '\0';
       
        for(iContIndex=0; iContIndex<=51; iContIndex++){
                ToCom (iComDisplay, cDispPacote[iContIndex]);
                DelayMs (2);
        }
       
        iDisplaySend=0;
}

---

EscreveDisplay ("LENKE AUTOMACAO", 0);

ok, i had no checked for len, and changed the code.

why this not ok ?
some \0 or like similliar ?

What, exactly, do you get as output? (and what do you expect?)

--
Mats

EscreveDisplay ("LENKE AUTOMACAO", 0);

output need be:

[10 chars prefix (0 to 9)]LENKE AUTOMACAO.........................[BCC][/0]

Quote:

---

Originally Posted by sergioms

EscreveDisplay ("LENKE AUTOMACAO", 0);

output need be:

[10 chars prefix (0 to 9)]LENKE AUTOMACAO.........................[BCC][/0]

---

Yes, and what do you get? [Sorry, I don't have time at this point to compile your code and test it myself].

--
Mats

[0] �
[1] ~
[2] .
[3]
[4]

[5]
[6]
[7]
[8] L
[9] Ê
[10] L
[11] E
[12] N
[13] K
[14] E
[15]
[16] A
[17] U
[18] T
[19] O
[20] M
[21] A
[22] C
[23] A
[24] O
[25] .
[26]
[27]
[28] [
[29] %
[30] i
[31] ]
[32]
[33] %
[34] c
[35]

[36]
[37]

[38]
[39]
[40]
[41]
[42] G
[43] #
[44] ;
[45] 
[46] Â
[47] 
[48] ;
[49] 
[50]

[51]

And exactly what code are you using for this - I copied your seconds sample code (the one with main), and adapted it to compile with gcc (remove conio.h and a few other bits like that), and it works just fine.

--
Mats

this code, i has guide by your tips...

Code:

---

#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void EscreveDisplay (unsigned char *pMensagem, unsigned int pDelaySec);

void main(void)
{
   
  // printf("Press any ket to begin\n\r");
  // printf("and press any key can reset the program.\n\r");
  // getch();
   
        EscreveDisplay ("LENKE AUTOMACAO", 0);
}

void EscreveDisplay (unsigned char *pMensagem, unsigned int pDelaySec){
        unsigned char cDispPacote [52];
        int iComDisplay = 2;
        unsigned int iLims;
        unsigned int iLenMsg, iLenCont, iContIndex;
        int iBcc;
       
      //        iDisplaySend = 1;
      //        if (pDelaySec > 0)
      //                Delay(pDelaySec * 1000);
       
        iLims  = 46;
       
        cDispPacote [0] = 129;
        cDispPacote [1] = 126;
        cDispPacote [2] = iLims % 256;
        cDispPacote [3] = iLims / 256;
        cDispPacote [4] = 1 % 256;
        cDispPacote [5] = 1 / 256;
        cDispPacote [6] = 0 % 256;
        cDispPacote [7] = 0 / 256;
        cDispPacote [8] = 76;
        cDispPacote [9] = 202;

        iLenMsg = strlen (pMensagem);

        for(iLenCont=iLenMsg; iLenCont<40; iLenCont++)
                strcat (pMensagem, ".");
       
        for(iLenCont=0; iLenCont<40; iLenCont++){
                iContIndex = iLenCont + 10;
                cDispPacote [iContIndex] = pMensagem [iLenCont];
        }
       
        iBcc = cDispPacote [4];
        cDispPacote [50] = iBcc;
        cDispPacote [51] = '\0';
       
        for(iContIndex=0; iContIndex<=51; iContIndex++){
                printf ("[%i] %c\n",iContIndex,cDispPacote[iContIndex]);
              //        DelayMs (2);
        }
       
        printf ("\n");
        getch ();
}

---

Code:

---

        for(iLenCont=iLenMsg; iLenCont<40; iLenCont++)
                strcat (pMensagem, ".");


---

This code is _STILL_ very much wrong - because you are modifying a constant variable, and who knows what happens if you do that. On my Windows system, compiling using gcc, I get a immediate crash.

If your compiler supports it, you could add

Code:

---

const char *pMensagem

---

to your header - but your compiler may not accept that.

--
Mats

i Have changed:

Code:

---

void EscreveDisplay (const char *pMensagem, unsigned int pDelaySec){

---

But compiler warning says: Suspicious pointer conversion in this line:

Code:

---

strcat (pMensagem, ".");

---

Quote:

---

Originally Posted by sergioms

i Have changed:

Code:

---

void EscreveDisplay (const char *pMensagem, unsigned int pDelaySec){

---

But compiler warning says: Suspicious pointer conversion in this line:

Code:

---

strcat (pMensagem, ".");

---

---

Exactly, because YOU SHOULD NOT DO THAT! You are writing to a constant - you have no right to modify that!

--
Mats

do you believe in the suspect of this a time to process serial receive string ?

I added DelayMs (2) after each of tocom and now, the system seems better, or no... i will test more this..

the serial com is 2400 of baudrate.

Quote:

---

Originally Posted by sergioms

do you believe in the suspect of this a time to process serial receive string ?

I added DelayMs (2) after each of tocom and now, the system seems better, or no... i will test more this..

the serial com is 2400 of baudrate.

---

If you have not fixed the strcat() to be like your other piece of code that writes '.' into the local string inside the function escreve...(), then I would not put any trust into what happens and what consequences any other changes makes.

--
Mats

15/1/2009 14:00:53 - Rec: ..........................

I had received ......... again, next to escreve () in the function EnviaPedidoPc.

otherwise,

sprintf can fill a specified repeated char in a string ?

like some:

sprintf (pMensagem, "%40c", '.');

Code:

---

for (iLenCont=10; iLenCont<=49; iLenCont++)
  cDispPacote [iLenCont] = '.';

---

There is NOTHING wrong with this code, as far as I can see. strcat or sprintf will definitely be slower an probably take up more code-space too.

--
Mats

yes, you're correct,

but here not run andd crash my system,

Or I have some problem and not see
Or this equipment isvery........ing crazy

strcat addd any \0 at end of string?

Quote:

---

Originally Posted by sergioms

when the program crashs, all outputs stop, and stop execution.

---

Yes so do them before it crashes ;)
You can use fflush to for it to write it's output.

Quote:

---

Originally Posted by esbo

Yes so do them before it crashes ;)
You can use fflush to for it to write it's output.

---

Not relevant here, I should think.

Figuring out WHY the system crashes is another better idea, I should think.

Yes, strcat() will put a zero on the end of the string - but as I said earlier, you should DEFINITELY NOT modify incoming constant strings (e.g. "Hello, World" passed to your function) - that is DEFINITELY VERY BAD. Never EVER is that right.

It is quite possible that you have other problems similar to this.

--
Mats

I've no idea what the current code looks like.

But anything involving strcat - of either the source or destination strings is broken.

Quote:

---

Originally Posted by matsp

Not relevant here, I should think.

Figuring out WHY the system crashes is another better idea, I should think.

Yes, strcat() will put a zero on the end of the string - but as I said earlier, you should DEFINITELY NOT modify incoming constant strings (e.g. "Hello, World" passed to your function) - that is DEFINITELY VERY BAD. Never EVER is that right.

It is quite possible that you have other problems similar to this.

--
Mats

---

THEN i need use

unsigned char *Test;

strcpy (Test, "LENKE AUTOMACAO");

EscreveDisplay (Test, 0);

?

That would be problematic. Test is only a (probably non-null) pointer that points to nowhere.

Quote:

---

Originally Posted by sergioms

15/1/2009 14:00:53 - Rec: ..........................

I had received ......... again, next to escreve () in the function EnviaPedidoPc.

otherwise,

sprintf can fill a specified repeated char in a string ?

like some:

sprintf (pMensagem, "%40c", '.');

---

Are you not writing to a constant again?

Quote:

---

Originally Posted by laserlight

That would be problematic. Test is only a (probably non-null) pointer that points to nowhere.

---

i believe in this, now i will test to try.

i use "TEXT" to argument,
next i use strlen function, then i suspect this not have a \0 char.

Quote:

---

Originally Posted by sergioms

THEN i need use

unsigned char *Test;

strcpy (Test, "LENKE AUTOMACAO");

EscreveDisplay (Test, 0);

?

---

But why - there is a perfectly fine solution there already which uses the "new" string which you CAN modify. And of course, as Laserlight says, you must either use a char array or allocate some memory (and make sure that's at least 41 bytes, if we use the above strcat() type code).

But I would prefer to not use strcat at all.

--
Mats

I MAKE A TEST WITH THIS CODE:

Code:

---

void EscreveDisplay (unsigned char *pMensagem, unsigned int pDelaySec){
        unsigned char cDispPacote [52];
        int iComDisplay = 2;
        unsigned int iLims;
        unsigned int iLenMsg, iLenCont, iContIndex;
        int iBcc;
       
        iDisplaySend = 1;
        if (pDelaySec > 0)
                Delay(pDelaySec * 1000);
       
        iLims  = 46;
       
        cDispPacote [0] = 129;
        cDispPacote [1] = 126;
        cDispPacote [2] = iLims % 256;
        cDispPacote [3] = iLims / 256;
        cDispPacote [4] = 1 % 256;
        cDispPacote [5] = 1 / 256;
        cDispPacote [6] = 0 % 256;
        cDispPacote [7] = 0 / 256;
        cDispPacote [8] = 76;
        cDispPacote [9] = 202;

        iLenMsg = strlen (pMensagem);
 
        for (iLenCont=10; iLenCont<=49; iLenCont++)
                cDispPacote [iLenCont] = '.';
       
        for(iLenCont=0; iLenCont<iLenMsg; iLenCont++){
                iContIndex = iLenCont + 10;
                cDispPacote [iContIndex] = pMensagem [iLenCont];
        }

        iBcc = cDispPacote [4];
        cDispPacote [50] = iBcc;
        cDispPacote [51] = '\0';
       
        for(iContIndex=0; iContIndex<=51; iContIndex++){
                ToCom (iComDisplay, cDispPacote[iContIndex]);
                DelayMs (2);
        }
       
        iDisplaySend=0;
}

---

and call this:

Code:

---

void UserCount(void)
{
        if (iDisplaySend == 0){
                VerificaBotoes ();
               
                if (iVazia)
                        RecebeSerial ();
               
                if (iPesaItem)
                        RecebeSerial ();
                       
                if (iStepTimer >= 1 && iStepTimer < 10)
                        iStepTimer++;
        }
}

void UserInit(void)
{
        unsigned char *MsgDisplay;
       
        InitLib();
       
        PortUser = 5050;        // Habilita porta 5050 para Controle do Usuário (Aplicação Objeto de Comunicação (Listener))
       
        // Transforma os Int em Char (ASCII)
        cSTX = 2;
        cCR  = 13;
        cLF  = 10;
        cTab = 9;
       
        IniciaSerial ();
        IniciaMemoria();
       
        strcpy (MsgDisplay, "LENKE AUTOMACAO 1");
        EscreveDisplay (MsgDisplay, 2);

                strcpy (MsgDisplay, "LENKE AUTOMACAO 2");
        EscreveDisplay (MsgDisplay, 2);

                strcpy (MsgDisplay, "LENKE AUTOMACAO 3");
        EscreveDisplay (MsgDisplay, 2);
       
    AddUserTimerFunction(UserCount, 200); // Adiciona  Timer para Chamar Função UserCount a cada 200  ms
}

---

and the resul is ok:

LENKE AUTOMACAO 1................................
LENKE AUTOMACAO 2................................
LENKE AUTOMACAO 3................................

BUT, AFTER THE SYSTEM HAS STOPPPED :\\\\\\\

> unsigned char *MsgDisplay;
> strcpy (MsgDisplay, "LENKE AUTOMACAO 1");
Seriously, learn C before you start messing about with embedded systems.

You're simply making far too many fundamental mistakes to have any success at all.

Embedded systems do not take prisoners, they do not negotiate and they won't tell you a damn thing about where you screwed up.

Quote:

---

Originally Posted by Salem

> unsigned char *MsgDisplay;
> strcpy (MsgDisplay, "LENKE AUTOMACAO 1");
Seriously, learn C before you start messing about with embedded systems.

You're simply making far too many fundamental mistakes to have any success at all.

Embedded systems do not take prisoners, they do not negotiate and they won't tell you a damn thing about where you screwed up.

---

ok, but now i have to resolve this case. :p

Whenever you see a * in your code, start paying attention.

Like, answering questions such as
- has it been initialised
- how much memory is it pointing at
- am what I am about to do with that memory OK from an array bounds perspective

Just declaring a pointer, then using it for strcpy takes none of these questions into account, and you get hosed for it.

Quote:

---

Originally Posted by sergioms

ok, but now i have to resolve this case. :p

---

You do it by learning C.
Step back. Get a book. Study the fundamentals. Mess around with PC software. Get the grap of all features.
Done all that? OK. Now you can get back to your project.

if i am use:

Code:

---

void EscreveDisplay (char pMensagem[17], unsigned int pDelaySec){

// then call by:

char cMsgtest[17];

strcpy (cMsgtest, "LENKE AUTOMACAO");

EscreveDisplay (cMsgtest);

---

its compile, run but my program crash at next call to EscreveDisplay...

Quote:

---

Originally Posted by sergioms

if i am use:

Code:

---

void EscreveDisplay (char pMensagem[17], unsigned int pDelaySec){

// then call by:

char cMsgtest[17];

strcpy (cMsgtest, "LENKE AUTOMACAO");

EscreveDisplay (cMsgtest);

---

its compile, run but my program crash at next call to EscreveDisplay...

---

Well, you do not need to specify [17] in the called function, just empty [] will do, or char *.

I do not see why you need to change the code to use strcpy() at all here - that would be the right solution if you update the string that you are passing into EscreveDisplay - but in the code you posted most recently, you are not actually doing that, so it should work fine just passing "LENKE AUTOMACAO" as the input to EscreveDisplay() [obviously with the correct number of parameters].

--
Mats