String Copying Probleming

Hello,

i'm trying to copy a const char* string (call it stringA) to a char* string (stringB).

now lets say stringA is 20 characters long and i only want to copy 10 of those characters to stringB. Whats the best possible way to go about doing it?

i've tried using a for loop..

Code:

---

int i;
for (i=0; i < 10; i++)
{
    stringB[i] = stringA[i];
}
stringB[i] = '\0';

---

... but this only results in a segmentation core fault.

then i tried using strncpy...

Code:

---

strncpy(stringB, stringA, 10);

---

.. but this isnt giving me the results i want. its copying the whole stringA into stringB.

what am i doing wrong? Any help would be great.

Thanks.

Could you post a complete program that isn't working? Your examples looks correct.

If stringB is declared like this:
char* stringB;
then you need to allocate memory with new.

Or declare it with at least 11 characters like this:
char stringB[11];

since it looks like you're using C-style strings, don't forget to add the '\0' at the end of the loop... most likely you're trying to write to space you never allocated...

this code compiles fine:

Code:

---

#include<iostream>

int main()
{
        int i;

        const char*stringA="This String is more than 10 characters long";
        char*stringB=new char[11];

        for(i=0;i<10;i++)
            stringB[i]=stringA[i];
        stringB[i]='\0';

        std::cout<<stringA<<std::endl<<stringB<<std::flush;

        std::cin.get();
        return 0;
}

---

don't forget to delete stringB when you're done with it too...