Stack in plugin

Wanted to use own plugin stack for data saving, but can't figure it out. nError=1, after pushstring_dll.

#include <windows.h>

#include <iostream.h>

#define NSIS_MAX_STRLEN 1024



typedef struct _stack_t_dll {

	struct _stack_t_dll *next;

	char text[NSIS_MAX_STRLEN];

} stack_t_dll;



stack_t_dll **g_stacktop;

int g_stringsize=NSIS_MAX_STRLEN;

//g_stacktop=???;



int popstring_dll(char *str);

void pushstring_dll(char *str);



void main()

{

	char szResult[1024]="";

	int nError;



	pushstring_dll("xxx");

	nError=popstring_dll(szResult);



	cout << "szResult={"<< szResult <<"} ("<< nError <<")"<<endl;

}



int popstring_dll(char *str)

{

	stack_t_dll *th;

	if (!g_stacktop || !*g_stacktop) return 1;

	th=(*g_stacktop);

	lstrcpy(str,th->text);

	*g_stacktop = th->next;

	GlobalFree((HGLOBAL)th);

	return 0;

}



void pushstring_dll(char *str)

{

	stack_t_dll *th;

	if (!g_stacktop) return;

	th=(stack_t_dll*)GlobalAlloc(GPTR,sizeof(stack_t_dll)+g_stringsize);

	lstrcpyn(th->text,str,g_stringsize);

	th->next=*g_stacktop;

	*g_stacktop=th;

}

Well... normally you can do that in pure C++

#include <iostream>
class Stack
{
public:
    Stack();
    ~Stack();
    void Push(const std::string&);
    int Pop(std::string&);
private:
    std::string s;
};
Stack::Stack()
{
    s = "";
}
Stack::~Stack()
{
    s = "";
}
void Stack::Push(const std::string& str)
{
    s = str;
}
int Stack::Pop(std::string& buff)
{
    if (s.empty()) return 0;
    buff = s;
    s = "";
    return 1;
}
int main()
{
    using namespace std;
    Stack stack;
    string buff1, buff2;
    int nError = 0;
    stack.Push("nsis");
    nError = stack.Pop(buff1);
    //0 = empty
    //1 = not empty
    cout << "Code: " << nError << "\nStack: " << buff1.c_str() << endl;
    nError = stack.Pop(buff2);
    cout << "Code: " << nError << "\nStack: " << buff2.c_str() << endl;
    stack.Push("nsis2.08");
    nError = stack.Pop(buff2);
    cout << "Code: " << nError << "\nStack: " << buff2.c_str() << endl;
    // wait until a keypress to exit
    cin.get();
    return 0;
} 

Thank you Joel! Work great, but I still wanted to find "C" solution (point of principle 🙂 )

At last:

#include <windows.h>

#include <iostream.h>



#define NSIS_MAX_STRLEN 1024



typedef struct _stack_dll {

	struct _stack_dll *next;

	char string[NSIS_MAX_STRLEN];

} stack_dll;



stack_dll *pStackTop;



int popstring_dll(char *str);

void pushstring_dll(char *str);



void main()

{

	char szResult1[1024]="";

	char szResult2[1024]="";

	int nError1;

	int nError2;



	pushstring_dll("xxx");

	pushstring_dll("YYY");

	nError1=popstring_dll(szResult1);

	nError2=popstring_dll(szResult2);



	cout << "szResult={"<< szResult1 <<"} ("<< nError1 <<")"<<endl;

	cout << "szResult={"<< szResult2 <<"} ("<< nError2 <<")"<<endl;

}



void pushstring_dll(char *str)

{

	stack_dll *pStackNew;

	pStackNew=(stack_dll*)GlobalAlloc(GPTR, sizeof(stack_dll));

	lstrcpyn(pStackNew->string, str, NSIS_MAX_STRLEN);

	pStackNew->next=pStackTop;

	pStackTop=pStackNew;

}



int popstring_dll(char *str)  //0 on success, 1 on empty stack

{

	stack_dll *pStackTemp;

	if (!pStackTop) return 1;

	pStackTemp=pStackTop;

	lstrcpy(str, pStackTemp->string);

	pStackTop=pStackTemp->next;

	GlobalFree((HGLOBAL)pStackTemp);

	return 0;

}

I found it interesting to playing with chain of structures.

Standart NSIS stack functions: push_front, pop_front;
Other stack functions: push_back, stack_read, stack_size.

#include <windows.h>

#include <iostream.h>



#define NSIS_MAX_STRLEN 1024



typedef struct _stack_dll {

	struct _stack_dll *next;

	char string[NSIS_MAX_STRLEN];

} stack_dll;



stack_dll *pStackFirst;

stack_dll *pStackTop;



void push_back(char *str);

void push_front(char *str);

int pop_front(char *str);

int stack_read(char *str, int index);

int stack_size();



void main()

{

	char szRes1[1024],szRes2[1024],szRes3[1024],szRes4[1024],szRes5[1024]="";

	char szRead[1024]="";

	int nEr1,nEr2,nEr3,nEr4,nEr5;

	int nErRead;

	int nSize;



	push_back("1a");

	push_back("2a");

	push_back("3a");

	push_front("4a");



	nErRead=stack_read(szRead, 2);



	nSize=stack_size();



	nEr1=pop_front(szRes1);

	nEr2=pop_front(szRes2);

	nEr3=pop_front(szRes3);

	nEr4=pop_front(szRes4);

	nEr5=pop_front(szRes5);



	cout << "szRes1={"<< szRes1 <<"} ("<< nEr1 <<")"<<endl;

	cout << "szRes2={"<< szRes2 <<"} ("<< nEr2 <<")"<<endl;

	cout << "szRes3={"<< szRes3 <<"} ("<< nEr3 <<")"<<endl;

	cout << "szRes4={"<< szRes4 <<"} ("<< nEr4 <<")"<<endl;

	cout << "szRes5={"<< szRes5 <<"} ("<< nEr5 <<")"<<endl;

	cout << "szRead={"<< szRead <<"} ("<< nErRead <<")"<<endl;

	cout << "nSize={"<< nSize <<"}"<<endl;

}



//Adds an element to the beginning of the stack.

void push_back(char *str)

{

	stack_dll *pStackNew;

	pStackNew=(stack_dll*)GlobalAlloc(GPTR, sizeof(stack_dll));

	lstrcpyn(pStackNew->string, str, NSIS_MAX_STRLEN);

	if (pStackFirst) pStackFirst->next=pStackNew;

	if (!pStackFirst) pStackTop=pStackNew;

	pStackFirst=pStackNew;

}



//Adds an element to the top of the stack.

void push_front(char *str)

{

	stack_dll *pStackNew;

	pStackNew=(stack_dll*)GlobalAlloc(GPTR, sizeof(stack_dll));

	lstrcpyn(pStackNew->string, str, NSIS_MAX_STRLEN);

	pStackNew->next=pStackTop;

	pStackTop=pStackNew;

	if (!pStackFirst) pStackFirst=pStackNew;

}



//Removes the element from the top of the stack and puts it in the buffer.

//Returns: 0 on success, 1 on empty stack

int pop_front(char *str)

{

	stack_dll *pStackTemp;

	if (!pStackTop) return 1;

	pStackTemp=pStackTop;

	lstrcpy(str, pStackTemp->string);

	pStackTop=pStackTemp->next;

	GlobalFree((HGLOBAL)pStackTemp);

	return 0;

}



//Finds the element with index and puts it in the buffer.

//Returns: 0 on success, 1 on empty stack

int stack_read(char *str, int index)

{

	stack_dll *pStackTemp=pStackTop;

	int sum;



	for (sum=1; (pStackTemp); ++sum)

	{

		if (sum == index)

		{

			lstrcpy(str, pStackTemp->string);

			return 0;

		}

		pStackTemp=pStackTemp->next;

	}

	return 1;

}



//Returns: the number of elements in the stack.

int stack_size()

{

	stack_dll *pStackTemp=pStackTop;

	int sum;



	for (sum=0; (pStackTemp); ++sum)

		pStackTemp=pStackTemp->next;

	return sum;

}

STL and vectors are easier, but as you said you want C style -_-