在编译时将const char *转换为char *

Question

In my project, I need the user to input a string, and the string that is typed is const char* by default (with using quotation marks). In my project, I also need to modify these strings, so I cannot really use const .

So I thought about transforming the const char* into a char* with the following function:

Not 100% sure this is the problem (since it crashes for me) but I believe the problem is that the New string does not have enough memory to store the whole string. I tried sort of allocating it memory by writing like this:

const char* szOldString = "Test";
char* szNewString[0x1024];
noconst(&szOldString, &szNewString, 5);

This also did not work considering my parameters and the constexpr.

---

I am wondering if anybody knows any cool hacks I can use to make this work. I have been working on this for some time so the solution might be an obvious one and I just cannot see it. If that's the case, my bad :D

Answer 1

The easier way is to use the function strncpy (which is more secure than just using strcpy).

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

using namespace std;

int main()
{
  //char oldString[]= "Hello World!";
  const char* oldString = "Hello World!";
  char newString[40];

  /* copy to sized buffer (overflow safe): */
  strncpy ( newString, oldString, sizeof(newString) );

  cout << newString;  

    return 0;
}

Another way is to allocate with malloc space for where you wish to copy the string. After, you can modify it at your please.

Let me know if this helped you out.