Thread: help with generic function

The following is an attempt at a generic uppercase function, not my code but im trying to understand it. I dont understand the garbagestring function, whats it most likely to be and say i had a string "hello" and wanted to use this function to 'uppercase it' what would i need to change?

thanks!

Code:

// --------------------------- UCase() function

char *UCase(char *);

char *UCase(char *UCaseString)

{

	char *StrUCaseTmp;

	int StrUCaseLen;

	StrUCaseLen=strlen(UCaseString);

	StrUCaseTmp=garbagestring(StrUCaseLen);

	strncpy(StrUCaseTmp,UCaseString,StrUCaseLen);

	StrUCaseTmp=strupr(StrUCaseTmp);

	return StrUCaseTmp;

}

Originally Posted by major_small

it looks to me like garbagestring is a pointer to some (semi)random data... IMO, that function looks like it could be quite dangerous if coded inproperly... I'm going to give you this code out of a recent project

This I coded like this only because they required char*'s, and I didn't have the option of using an external buffer:

Code:

char*capitalize(const char*in)
{
	std::string buf=in;
	for(register short unsigned int i=0;i<buf.length();i++)
	{
		buf[i]=toupper(buf[i]);
	}
	return const_cast<char*>(buf.c_str());
}

and here's how I'd suggest doing it:

Code:

std::string PXRUsers::capitalize(const std::string in)
{
	std::string retval=in;
	for(register unsigned int i=0;i<in.length();i++)
	{
		retval[i]=toupper(retval[i]);
	}
	return retval;
}

Thanks! your code looks fine but the thing is that i have loads of these functions, pretty much every function you can get , lcase, mid, split, instr, etc.. coded generically in a sense. The point was to take VB code and turn it into C++. Now the guy that wrote all these corresponding C++ functions really knows what he's doing, you can tell by the code. So basically your saying this code looks dodgy ? If i could understand te garbagestring and add a function for it i would be away.

Ok i found the garbagestring function. I put it all together. Can anybody make any sense of it?

Code:

#include <iostream>
#include <windows.h>

char *UCase(char *);
char *garbagestring(DWORD StrBytes);
void initgarbage(void);
int GarbagePos;
char *GarbageArray[0x4000];

__inline void AsmPointerFill(DWORD,DWORD,DWORD);
__inline void *MallocZero(size_t);

char *garbagestring(DWORD StrBytes)
{
	char *CurrentGarbage;

	if (GarbageArray[GarbagePos]) free((void *)GarbageArray[GarbagePos]);

	CurrentGarbage=(char *)MallocZero(StrBytes+1);

	GarbageArray[GarbagePos]=CurrentGarbage;

	GarbagePos=(GarbagePos+1)&0x3fff;

	return CurrentGarbage;
}

char *UCase(char *UCaseString)
{

	char *StrUCaseTmp;

	int StrUCaseLen;

	StrUCaseLen=strlen(UCaseString);

	StrUCaseTmp=garbagestring(StrUCaseLen);

	strncpy(StrUCaseTmp,UCaseString,StrUCaseLen);

	StrUCaseTmp=strupr(StrUCaseTmp);

	return StrUCaseTmp;

}


__inline void *MallocZero(size_t SizeToAlloc)
{
	DWORD AllocatedMem;
	AllocatedMem=(DWORD)malloc(SizeToAlloc);
	AsmPointerFill(AllocatedMem,0,SizeToAlloc);
	return((void *)AllocatedMem);
}


__inline void AsmPointerFill(DWORD MemToFill,DWORD FillDat,DWORD FillLen)
{
	_asm {
		push eax
		push ecx
		push edi
		mov edi,MemToFill
		mov ecx,FillLen
		mov eax,FillDat
		cld
		shr ecx,2
		rep stosd
		mov ecx,FillLen
		and ecx,3
		rep stosb
		pop edi
		pop ecx
		pop eax
	}
	return;
}

int main(){
    
 UCase("hello");  
    
}

As garabgestring is always associated with strncopy and the format of strncopy is,

Code:

char *strncpy(char *dest, const char *src, size_t n);

an example being,

Code:

char str1[]= "To be or not to be";
  char str2[6];
  strncpy (str2,str1,5);

so its and temp array to hold the string, so why has this code got what its got basically ?

Could i just say

char garabgestring[];

?

Whats the difference between char and char* ??

Also how can i declare a dynamic array i.e

garbagestring[]; That gives me an error telling me its undimensioned ?

Finally whats wrong with this,

Code:

#include <iostream>

using namespace std;
int main (){
  
                }

char *UCase(char *UCaseString)
{

	char *garbagestring[100]; // ideally redimension array
	//  garbagestring[strlen(UCaseString)???	
	
	char *StrUCaseTmp;

	int StrUCaseLen;

	StrUCaseLen=strlen(UCaseString);

	strncpy(garbagestring,UCaseString,StrUCaseLen);

	StrUCaseTmp=strupr(garbagestring);

	return StrUCaseTmp;

}

This gives me the error,

cannot convert `char**' to `char*' for argument `1' to `char* strncpy(char*, const char*, size_t)' at line,

strncpy(garbagestring,UCaseString,StrUCaseLen);.

thanks again for any help!

I think i see what the code was doing, could be wrong but, i think it was creating an array of size strlen(UCaseString) in other words,

Code:

garbagestring[strlen(UCaseString];

Is there another way to set a char array to a specific size ?

I need to say,

Code:

char garbagestring[];

//code

garbagestring = garbagestring[strlen(UCaseString];

Excellent, thanks for all the help.!