split by blank implementation

split_by_blank.c

#include "stdafx.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

//return value:  the pointer used to free the allocated buffer
char* split_by_blank(char * input, char **& output, size_t& item_count, size_t max_item_count)
{
	if (max_item_count <= 0)
	{
		return NULL;
	}

	if (!input)
	{
		return NULL;
	}

	size_t length = strlen(input);
	char* buffer = (char*)malloc(length + 1);

	memcpy(buffer, input, length + 1);
	output = (char**)malloc(max_item_count * sizeof(char**));

	int last_is_space = 0;
	char* last_pointer = buffer;
	size_t item_index = 0;

	for (size_t i = 0; i < length + 1; ++i)
	{
		if (input[i] == ' ')
		{
			buffer[i] = '\0';
			last_is_space = 1;
		}
		else
		{
			if (last_is_space || i == length)
			{
				if (item_index >= max_item_count)
				{
					break;
				}

				if (*last_pointer != '\0')
				{
					output[item_index++] = last_pointer;
				}

				last_pointer = &buffer[i];
			}

			last_is_space = 0;
		}
	}

	item_count = item_index;

	return buffer;
}

int _tmain(int argc, _TCHAR* argv[])
{
	using namespace std;

	char **output;
	size_t count;
	char* buffer = split_by_blank("  apple banana orange peach pear", output, count, 5);

	if (buffer)
	{
		for (int i = 0; i < count; i++)
		{
			printf("%s\r\n", output[i]);
		}

		free(buffer);
		free(output);
	}

	return 0;
}