Question

I am having trouble with the basic principles of strings in C.
I have a function:

char *editStr(char *str) {
char new[strlen(str)];
... do some editing ...
return new;
}

How would I return the array of characters called “new”. As I understand, the return value of the function is a char*, which means that it is asking for a pointer to the first character of a string.
Right now, I guess the problem is that I am returning a character of arrays. I tried to return a pointer to the first character in “new”, but that doesn’t seem to work, either.
I tried “return *new[0]”.
My string knowledge is bad.

Answer 1

There are various problems here but the array/pointer issue with return new; isn’t one of them.

First, you want:

char new[strlen(str) + 1];

So that you have enough room for the null terminator.

Your new is allocated on the stack so returning it will only cause grief and confusion; you’ll want to:

char *new = malloc(strlen(str) + 1);

instead so that the memory is still valid when the function returns.

As far as your real question goes, an array in C is the address of the first element so your return new; is fine (subject to the stack versus heap issue noted above). C arrays decay to pointers at the drop of a hat so you don’t need to worry about returning an array when the function is declared to return a pointer.