Null String

[sergioms]

char *InBuf;	   			

//.................

int RecebeSerial(void){

    int iLenBuf, iReadReturn;
		
	if(IsCom(iComBalanca)){
		iLenBuf = DataSizeInCom (iComBalanca);	
		iReadReturn = ReadComn(iComBalanca, InBuf, iLenBuf);
		
		InBuf [iLenBuf] = '\0';
		
		if (iReadReturn >= 0){	
			ProcessaBuffer (InBuf);
		}
		
		return 1;
	}
	
	return -1;
}

int strrpos (char *pStrText, char pChar){
	
	int iLen, iCont;
	iLen = strlen (pStrText);

	printCom1 (pStrText);
	printCom1 ("\nSTR.: %s", pStrText);
	printCom1 ("\nSTR1: %s", pStrText[1]);
	printCom1 ("\nBUF.: %s", InBuf);
	printCom1 ("\nLEN.: %d", iLen);
	
	if (iLen > 0){
		for (iCont=iLen - 1; iCont>=0; iCont--){
			if (pStrText[iCont] ==  pChar)
				return iCont;
		}
		return 0;	// Não houve ocorrências
	}
	else { return 0; }	// String Nula
}

void ProcessaBuffer (char *pInBuf){

	char cChar;
	unsigned char *cPacote, *cPeso;
	unsigned char *cStatus;
	unsigned char cByte;
	int iCont;
	int iPosStart, iPosEnd, iPosTam; 

	cChar = STARTCHAR; 
	iPosStart = strrpos (pInBuf, cChar);
	
	//...

strpos return:

1234567890AB
STR.: (null)
STR1: ?
BUF.: (null)
LEN.: 0 STARTCHAR:  INT: 2 Posição: 0


When i call strpos funcion, and use printCom1 (simillar printf) then result is ok, when I use %s or manipulate it string package is null.

Sorry for my english.

[matsp]

So are you actually assigning inbuf with anything?

--
Mats

[sergioms]

So are you actually assigning inbuf with anything?

--
Mats

Yes,

With Received Buffer in Serial (RecebeSerial):

iReadReturn = ReadComn(iComBalanca, InBuf, iLenBuf);

And add a '\0'

InBuf [iLenBuf] = '\0';

After, I Call strpos function.

[matsp]

But ReadComm takes the inbuf as a parameter, not as a pointer, so ReadComm can not update the pointer.

--
Mats

[sergioms]

int ReadComn(int port, unsigned char *buf, int n);

Then, What I can make to use correctly ?

[matsp]

int ReadComn(int port, unsigned char *buf, int n);

Then, What I can make to use correctly ?

Either pass buf as unsigned char ** (and use &inbuf in the calling code), or use a different mechanism to assign the inbuf to some memory location.

--
Mats

[sergioms]

Ok, i have modified to unsigned char, and calling inbuf with &, but the result is:

`1>ÿßâñhá
STR.: `1>ÿßâñhá
STR1: ?
BUF.: `1>ÿßâñhá
LEN.: 11STARTCHAR: INT: 2 Posição: 0
ïHO
STR.: ïHO
STR1:
BUF.: ïHO
LEN.: 3 STARTCHAR: INT: 2 Posição: 0

And the Compiler Warning: Suspicous pointer converter.

[matsp]

There is no way for me to tell if that is correct or not.

--
Mats

[sergioms]

ok, ok sorry.

[CODE]
iReadReturn = ReadComn(iComBalanca, &InBuf, iLenBuf);
...
ProcessaBuffer (&InBuf);

................

int strrpos (unsigned char *pStrText, char pChar){ // Última ocorrência do caractere.

int iLen, iCont;
iLen = strlen (pStrText);

printCom1 ("\nSTR.: %s", &pStrText);
printCom1 ("\nLEN.: %d", iLen);

.........

void ProcessaBuffer (unsigned char *pInBuf){

char cChar;
unsigned char *cPacote, *cPeso;
unsigned char *cStatus;
unsigned char cByte;
int iCont;
int iPosStart, iPosEnd, iPosTam;

cChar = STARTCHAR;
iPosStart = strrpos (&pInBuf, cChar);
...
[CODE]

Send: 1234567890AB

Result:

STR.: 123
LEN.: 14STARTCHAR:  INT: 2 Posição: 0

[sergioms]

ok, ok sorry.

[CODE]
iReadReturn = ReadComn(iComBalanca, &InBuf, iLenBuf);
...
ProcessaBuffer (&InBuf);

................

int strrpos (unsigned char *pStrText, char pChar){ // Última ocorrência do caractere.

int iLen, iCont;
iLen = strlen (pStrText);

printCom1 ("\nSTR.: %s", &pStrText);
printCom1 ("\nLEN.: %d", iLen);

.........

void ProcessaBuffer (unsigned char *pInBuf){

char cChar;
unsigned char *cPacote, *cPeso;
unsigned char *cStatus;
unsigned char cByte;
int iCont;
int iPosStart, iPosEnd, iPosTam;

cChar = STARTCHAR;
iPosStart = strrpos (&pInBuf, cChar);
...
[CODE]

Send: 1234567890AB

Result:

STR.: 123
LEN.: 14STARTCHAR:  INT: 2 Posição: 0

[hk_mp5kpdw]

What's the code for ReadComn? Looks like you're getting confused with syntax. You're using &pInBuf, &InBuf and &pStrText in places where it is incorrect/inappropriate to do so and I suspect you're tripping over yourself.

[sergioms]

int ReadComn(int port, unsigned char *buf, int n);

then...How to Call this functions?

[matsp]

Well, if you want to MODIFY what the parameter buf points to, you need to have a double pointer so that you can do something like *buf = newplace.

--
Mats

[sergioms]

Oh god, sorry i don't undestand.

Can you show me an example please?

[hk_mp5kpdw]

Not the function prototype, the actual code for the ReadComn function.

If the parameter you're passing into the function needs to be changed then you need to pass an address (a pointer) to whatever you plan on changing. If what you plan on changing is already a pointer, then you need to pass in a pointer to a pointer and inside the function that will be making the change you'd modify it's value (such that the value is changed in the calling function) by doing like matsp stated above. This does not mean that you stick a & in front of every array/pointer variable in your code:

Some examples of you missuse of &... Assuming InBuf is declared as an unsigned char*, then:

// This is fine as long as the pointer InBuf needs to be modified by the ReadComn function
// and the function is defined to accept an unsigned char** and not an unsigned char*.
// In the function, you'd change its value by doing *buf = something
iReadReturn = ReadComn(iComBalanca, &InBuf, iLenBuf);
...
// This is likely incorrect, the function is declared as taking an unsigned char* but &InBuf in this
// case is a unsigned char** notice the extra *.  Does ProcessaBuffer also need to modify the
// pointer's value?  If it does, then the function needs to accept an unsigned char** like ReadComn
// If not, then you certainly don't want to use the &
ProcessaBuffer (&InBuf);

................

int strrpos (unsigned char *pStrText, char pChar){ // Última ocorrência do caractere.

int iLen, iCont;
iLen = strlen (pStrText);

// This is incorrect, you use it correctly above with the strlen function (without the &)
// but then you mess it up by putting the & back in here.
printCom1 ("\nSTR.: %s", &pStrText);
printCom1 ("\nLEN.: %d", iLen);

.........

void ProcessaBuffer (unsigned char *pInBuf){

char cChar;
unsigned char *cPacote, *cPeso;
unsigned char *cStatus;
unsigned char cByte;
int iCont;
int iPosStart, iPosEnd, iPosTam;

cChar = STARTCHAR;
// This here needs to change to just pInBuf.  pInBuf  is an unsigned char*.
// &pInBuff would therefore be a unsigned char** but the strrpos function accepts an unsigned char*
// You'd therefore need to use just pInBuf instead.
iPosStart = strrpos (&pInBuf, cChar);
...