String Copying Probleming

[PCV]

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..

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...

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.

[Sang-drax]

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

[swoopy]

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];

[major_small]

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:

#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...