Converts a string into a heap-allocated array of integers

str_to_intarr.c

long unsigned int byte_instances(char* bytes, long unsigned int len, char byte){
  long unsigned int inst=0;
  for(long unsigned int i=0;i<len;i++){
     if(bytes[i]==byte){
       inst++;
     }
  }
  return inst;
}

long unsigned int char_instances(char* bytes, char byte){
  long unsigned int inst=0;
  for(long unsigned int i=0;bytes[i]!=0;i++){
     if(bytes[i]==byte){
       inst++;
     }
  }
  return inst;
}

long unsigned int until_byte(char* bytes, long unsigned int n,char byte){
	long unsigned int until;
	for(until=0;until<n;until++){
		if(bytes[until]==byte){
			return until;	
		}
	}

	return n;
}


long unsigned int until_char(char* bytes, char byte){
  long unsigned int until;
	for(until=0;bytes[until]!=0;until++){
		if(bytes[until]==byte){
			return until;	
		}
	}

	return until;
}

int* str_to_intarr(char* str, char sep, long unsigned  int* len){
  long unsigned int i;
  long unsigned int inst=char_instances(str, sep);
  int* ints=(int*)malloc(inst*sizeof(int));
  long unsigned int added_i=0;
  for(i=0;i<inst;i++){
    ints[i]=atoi(str+added_i);
    added_i+=(until_char(str, sep)+1);
  }
  ints[i]=atoi(str+added_i);
  *len=inst;
  return ints;
}