Const char * as block variable - objective-c

Question

Some relevant info I am on OSX using GCD in Objective-C. I have a background task that produces a very large const char * this is then re-introduced into a new background task. This cycle repeats essentially until the const char* is empty. Currently I am creating and using NSStrings in the blocks and then going back to char* immediately. As you can imagine this does a ton of unnecessary copying of all that.
I am wondering how __block variables work for non-objects or how I can get away from NSStrings?
Or
How is memory managed for non-object types?
It is currently just blowing up with ~2 gigs of memory all from the strings.
Here is how it currently looks:
-(void)doSomething:(NSString*)input{
__block NSString* blockCopy = input;
void (^blockTask)(void);
blockTask = ^{
const char* input = [blockCopy UTF8String];
//remainder will point to somewhere along input
const char* remainder = NULL;
myCoolCFunc(input,&remainder);
if(remainder != NULL && remainder[0] != '\0'){
//this is whats killing me the NSString creation of remainder
[self doSomething:#(remainder)];
}
}
/*...create background queue if needed */
dispatch_async(backgroundQueue,blockTask);
}

Answer 1

There is no need to use NSString at all and no need to use the __block attribute:
-(void)doSomething:(const char *)input{
void (^blockTask)(void);
blockTask = ^{
const char* remainder = NULL;
myCoolCFunc(input,&remainder);
if(remainder != NULL && remainder[0] != '\0'){
[self doSomething:remainder];
}
}
/*...create background queue if needed */
dispatch_async(backgroundQueue,blockTask);
}
There is also little need to use recursion either, as an iterative approach is also possible.
blockTask = ^{
const char* remainder = NULL;
while (YES) {
myCoolCFunc(input,&remainder);
if(remainder == NULL || remainder[0] == '\0')
break;
input = remainder;
}
}