Thread: Anyone can help me?

The code's function is decribed as follow,but it doesn't work.The problem must be caused by the line "strcpy(pStr,temp);//This line caused the problem,so why?"
--but i don't know why.Any suggestion will be helpful,thanks advanced.

Code:

//This function loop shift the string right by nsteps,for example,if "1234" input,the output will be "3421"

#include <string.h>
#include <iostream.h>

#define MAX_LEN  20

int LoopMove(char *pStr,int nSteps);

int main()
{
	char *pStr = "0123";
	int nSteps = 2;
	
	LoopMove(pStr,nSteps);

	return 0;
}

int LoopMove(char *pStr,int nSteps)
{
	char temp[MAX_LEN];
	int n;
	
	n = strlen(pStr) - nSteps;
	
	strcpy(temp,pStr + n);
	
	strcpy(temp + nSteps,pStr);
	
	*( temp + strlen(pStr) )= '\0';
	
	strcpy(pStr,temp);//This line caused the problem,so why?

	cout<<pStr<<endl;

	cout<<temp<<endl;

	cout<<strlen(pStr)<<" equal to "<<strlen(temp)<<endl;
	
	return 0;
}

When you define

Code:

char *pStr = "0123";

I suspect the compiler has put the string into a protected part of memory. You are trying to write over it in your function.

Todd

Thanks for you two guys' advice.
aha,i use VC++ 6.0 to edit and compile the source code,so i choose "cout" to print something instead of "printf" just for convenience.

after your advice,i have resolved the problem.But can you explaint if for me?
I declare:
char *pStr = "1234";//here,it is not a " const char *pStr = "1234" ",why i can't use the strcpy() to rewrite it?
thanks

Hi,Salem
what does your profile mean?
are you suggesting to use int main rather than void main?

got it,thanks a lot.